Low boost on O.CT chipped RS6

[cmore]

Everyone,

I have an 03' RS6 with the O.CT engine and transmission chip, K&N, Milltek downpipes, cats, and exhuast, and hyperboost DVs on a car with 31,000 miles.

I just installed a VDO boost gauge today and it looks great, but it is reading 12psi MAX and bleeds off to around 10psi at redline. I thought maybe I have a hole or leak in the gauge line so I ran a new one outside of the car, through the window, and into the gauge as a test. I had the exact same readings of 10-12psi. During idle it is reading 20 Hg of vacuum.

I read the O.CT chip should be running 16psi and I'm seeing 4psi less than that. Today is in the 30s F here in Pennsylvania.

The car has 93 octane in it or at least that is what the pump said. I also replaced the rubber hoses going to the DVs in case one of them had a leak, but no difference.

I do have a VAGCOM, but I can't record block 115 because the battery is dead in my laptop and won't run without being plugged in. While I'm sourcing a new battery do you guys have any idea?

Before putting in the gauge I've noticed the car doesn't seem to have as much power as normal and then later it is fine. I'm almost leaning toward replacing the N75.

Any other ideas? I assume most will want to see a log of block 115.

Thanks,
Chris

[DHall1]

Chris,

Before you go running up trees you are correct. We need block 115.

You need to know what the "ecu is asking for" on boost before you determine if there is a problem.

It sounds like stock boost level to me.

[peiserg]

do you know what you are supposed to be getting? STOCK boost is 800mb. thats 11.7psi

my oct has always maxed at something like 2050mb requested. that's 15.4 psi

the car picked up 120 lbft of tq and 70hp at the wheels with that.

have you just now had the oct work done? or did the car feel slow so you added the boost guage?

Sounds like your car might not have accepted the reflash. did you pay for it yourself, or took he car from someone who claimed the car was reflashed?

gotta get your block 115 logged, Holmes. Tru dat.

one other cheap option is replace N75 valve. thats where most techs seem to start when i have an issue.

G to the P.

[cmore]

I just bought the car a month ago and the previous owner had all of the work done to it. I've had times where the car seemed very quick and other times it seems decently quickly. Trying to do a launch is where it is noticeable. When the power is there all 4 wheels will slightly spin - but now it doesn't seem to have the power.

Is it possible that the 93 octane fuel I put in it was really 91 and it is retarding the timing and lowering the boost?

I'm positive it has the o.ct program, because the car has a lot of aftermarket parts to handle the extra power and the guy had tons of money.

It very well could be the N75. There are two of them, right?

What is the chance that the VDO gauge is not working right and is reading wrong?

Though first step is to log block 115 and see if the computer and the gauge match.

I'm putting my money on the N75 given that I know I've driven it with different power levels. I just put in the gauge today so I will now be able to tell if it ever gets up to 15-16psi.

Thanks,
Chris

[DHall1]

Chris,

You dont seem to understand what we are saying.

Log 115 will tell you two things.

1. What the ecu is asking for in terms of boost.
2. What the car is building in terms of boost.

Your vdo gauge has an answer to #2.

Its #1 that we are looking for.

N75 is a waste of money right now.

You cant even be sure the ecu is chipped until you see what the answer to #1 is.




I just bought the car a month ago and the previous owner had all of the work done to it. I've had times where the car seemed very quick and other times it seems decently quickly. Trying to do a launch is where it is noticeable. When the power is there all 4 wheels will slightly spin - but now it doesn't seem to have the power.

Is it possible that the 93 octane fuel I put in it was really 91 and it is retarding the timing and lowering the boost?

I'm positive it has the o.ct program, because the car has a lot of aftermarket parts to handle the extra power and the guy had tons of money.

It very well could be the N75. There are two of them, right?

What is the chance that the VDO gauge is not working right and is reading wrong?

Though first step is to log block 115 and see if the computer and the gauge match.

I'm putting my money on the N75 given that I know I've driven it with different power levels. I just put in the gauge today so I will now be able to tell if it ever gets up to 15-16psi.

Thanks,
Chris

[cmore]

I understand - I ordered a battery for my laptop today so I can log block 115. I can't log anything now, because the laptop won't hold a charge when not plugged in.

I'm not going to do anything else until I log block 115 as it will immediately tell me the direction I need to go.

[DHall1]

Buy a power converter for the 12v ash tray plug.




I understand - I ordered a battery for my laptop today so I can log block 115. I can't log anything now, because the laptop won't hold a charge when not plugged in.

I'm not going to do anything else until I log block 115 as it will immediately tell me the direction I need to go.

[bruce]

Buy a power converter for the 12v ash tray plug.

Another good idea!

[ttrs6]

change your n75 i had the same problem at 6 psi.if you installed a boost gauge you can change the n75.

[cmore]

Ok, I've logged block 115 and I created a graph with the results of a launch through 3rd gear.

I uploaded the PDF to drop.io here:

http://drop.io/kmlwdt25275/asset/rs6-010710-pdf

Here is the source data in Excel:

http://drop.io/ysgv0on/asset/rs6-010710-xlsx

The temperature is still in the 20s and 30s degrees F and I heard on another board there is a good chance that the ECU is lowering boost during these cold conditions. Is that true?

Check out the data and let me know what you think.

Thanks,
Chris

[cmore]

Here's all the raw data and I created two more columns that converted the atmospheric pressure to PSI. Now I know my gauge is right, because those are the same numbers I am seeing:



time rpm load mbar specified mbar actual mbar specified adj mbar actual adj
264.25 760 22.6 950 970 -0.145 0.145
264.43 720 22.6 950 970 -0.145 0.145
264.61 720 22.6 950 970 -0.145 0.145
264.79 720 23.3 950 970 -0.145 0.145
264.97 680 24.1 950 970 -0.145 0.145
265.15 720 24.8 950 970 -0.145 0.145
265.33 680 24.8 950 970 -0.145 0.145
265.51 680 24.8 950 970 -0.145 0.145
265.69 680 24.8 950 970 -0.145 0.145
265.87 680 27.1 950 970 -0.145 0.145
266.05 800 32.3 950 970 -0.145 0.145
266.23 1000 38.3 950 970 -0.145 0.145
266.41 1280 43.6 950 970 -0.145 0.145
266.59 1400 44.4 950 970 -0.145 0.145
266.77 1480 45.1 950 980 -0.145 0.29
266.95 1520 46.6 950 980 -0.145 0.29
267.13 1560 48.1 950 990 -0.145 0.435
267.31 1600 51.1 950 1000 -0.145 0.58
267.49 1680 54.1 950 1010 -0.145 0.725
267.67 1800 60.9 1810 1020 12.325 0.87
267.84 2040 75.9 1730 1030 11.165 1.015
268.01 2200 80.5 1790 1080 12.035 1.74
268.18 2360 87.2 1810 1160 12.325 2.9
268.35 2560 97 1810 1240 12.325 4.06
268.53 2800 108.3 1820 1370 12.47 5.945
268.7 3160 123.3 1840 1550 12.76 8.555
268.87 3600 144.4 1820 1740 12.47 11.31
269.04 4000 155.6 1820 1820 12.47 12.47
269.21 4400 155.6 1840 1810 12.76 12.325
269.39 4720 153.4 1860 1780 13.05 11.89
269.58 5200 150.4 1860 1740 13.05 11.31
269.75 5640 142.1 1840 1680 12.76 10.44
269.93 6040 139.1 1890 1650 13.485 10.005
270.11 6400 136.8 1880 1700 13.34 10.73
270.3 6640 139.8 1850 1750 12.905 11.455
270.47 6600 139.8 1860 1910 13.05 13.775
270.66 6320 139.8 1870 1760 13.195 11.6
270.83 5640 143.6 1840 1610 12.76 9.425
271.02 5080 148.1 1770 1640 11.745 9.86
271.19 5200 145.9 1760 1650 11.6 10.005
271.36 5360 144.4 1770 1650 11.745 10.005
271.55 5520 139.1 1790 1660 12.035 10.15
271.73 5600 143.6 1810 1680 12.325 10.44
271.91 5840 145.1 1840 1690 12.76 10.585
272.09 6000 144.4 1860 1730 13.05 11.165
272.27 6200 145.9 1860 1760 13.05 11.6
272.44 6360 144.4 1860 1780 13.05 11.89
272.62 6480 142.1 1860 1780 13.05 11.89
272.79 6640 139.1 1830 1790 12.615 12.035
272.97 6640 145.9 1820 1820 12.47 12.47
273.15 6320 150.4 1850 1840 12.905 12.76
273.34 5640 166.9 1840 1830 12.76 12.615
273.52 4920 168.4 1760 1900 11.6 13.63
273.7 4960 176.7 1750 1930 11.455 14.065
273.88 5000 172.2 1740 1890 11.31 13.485
274.06 5040 166.2 1740 1810 11.31 12.325
274.24 5120 160.2 1750 1760 11.455 11.6
274.42 5200 154.1 1760 1720 11.6 11.02
274.6 5280 154.1 1770 1710 11.745 10.875
274.78 5400 151.9 1780 1700 11.89 10.73
274.96 5440 153.4 950 1730 -0.145 11.165
275.14 5440 91.7 950 1980 -0.145 14.79
275.32 5320 20.3 950 1630 -0.145 9.715
275.5 4920 12.8 950 1310 -0.145 5.075
275.68 4400 14.3 950 1160 -0.145 2.9
275.85 4000 15 950 1110 -0.145 2.175
276.03 3520 13.5 950 1070 -0.145 1.595
276.21 3160 11.3 950 1050 -0.145 1.305
276.39 3080 10.5 950 1040 -0.145 1.16

[DHall1]

Looks like a stock RS6 data log.

Actual is running very close to called for except for a couple of spots around 5500. I would log a few more runs.

Cold weather will NOT cause the ECU to LOWER called for boost levels.




Chris,

You dont seem to understand what we are saying.

Log 115 will tell you two things.

1. What the ecu is asking for in terms of boost.
2. What the car is building in terms of boost.

Your vdo gauge has an answer to #2.

Its #1 that we are looking for.

N75 is a waste of money right now.

You cant even be sure the ecu is chipped until you see what the answer to #1 is.

[DHall1]

Looking back at your symptoms.

It could be the first signs of the transmission but not in the logs you posted.

Or the ECU is just stock.

Except for a couple of spots around 5500 the actual is reaching the called for boost level.

My first guess....stock ecu


Everyone,

I have an 03' RS6 with the O.CT engine and transmission chip, K&N, Milltek downpipes, cats, and exhuast, and hyperboost DVs on a car with 31,000 miles.

I just installed a VDO boost gauge today and it looks great, but it is reading 12psi MAX and bleeds off to around 10psi at redline. I thought maybe I have a hole or leak in the gauge line so I ran a new one outside of the car, through the window, and into the gauge as a test. I had the exact same readings of 10-12psi. During idle it is reading 20 Hg of vacuum.

I read the O.CT chip should be running 16psi and I'm seeing 4psi less than that. Today is in the 30s F here in Pennsylvania.

The car has 93 octane in it or at least that is what the pump said. I also replaced the rubber hoses going to the DVs in case one of them had a leak, but no difference.

I do have a VAGCOM, but I can't record block 115 because the battery is dead in my laptop and won't run without being plugged in. While I'm sourcing a new battery do you guys have any idea?

Before putting in the gauge I've noticed the car doesn't seem to have as much power as normal and then later it is fine. I'm almost leaning toward replacing the N75.

Any other ideas? I assume most will want to see a log of block 115.

Thanks,
Chris

[peiserg]

stock ecu. write to OCT/stratmosphere with the VIN number. they'll have a record of whether or not the car received a reflash. they should allow you to reflash it if it was paid for.

[cmore]

What the heck? Stock ECU?

I just bought the car from an Audi dealership and the previous owner had all the work recently done at Stratmosphere and car was suppose to have:

O.CT engine chip
O.CT transmission chip option
PSS9 Coil over and 9-way adjustable dampers and springs
Hotchkis sport front and rear sway bars
K&N air filter
Milltek stainless steel cat-back exhaust systems
Milltek turbo downpipes with high flow cats
Hyperboost diverter valves

I've checked and it has all of that and I'm trying to verify the chip. All those mods are things you do when you've chipped a car. Most people wouldn't do all of that on a stock car.

Is it possible that the dealership flashed it back to stock?

I'm going to have to make a call tomorrow.

Thanks,
Chris

[cmore]

I just talked to Bob from Stratmosphere and he said the appropriate chip for my RS6 is not a flash, but a solder in chip! So if that is the case there is no way that it could have got un-flashed.

Is it possible to beak into the ECU and see if I can see a O.CT chip soldered on? I know I could on my 1.8T from APR.

Thanks,
Chris

[MaxRS6]

Bob is a good guy to deal with in my experience. He shot me straight about some downpipes and their valves I recently purchased from them. He was always responsive and answered questions promptly and professionaly. Just my less than .03 worth.

I would assume you could see the chip as it is physical. I think you would need some bolts to put the ECU back together after you busted open the ECU. I'm sure Bob could also answer the question. It would seem they would be able to look up your VIN to see if it is in their system.

[peiserg]

i'll have to call Bobalicious myself. I have the OCT chip (which is actually a reflash). I don't see why you couldn't have the reflash, although bob himself would know best. make sure he verifies via your VIN number. and you can easily tell if the ecu has been physically opened. just look on the box itself. you cannot remove the ecu without removing a set of non-replaceable screws. if the non-replaceable screws are present, then your ecu was never removed.

i should call him to ask about the chip solder. what is that vs. my reflash?

[cmore]

This is getting more weird every day. Stratmosphere has no record of my VIN number being at their shop. I pulled the ECU tonight, temper screws were in, and no soldered on chips found in the ECU!

Not sure where to go from here....

[DHall1]

Sounds like its time for a reflash.




Chris,

Before you go running up trees you are correct. We need block 115.

You need to know what the "ecu is asking for" on boost before you determine if there is a problem.

It sounds like stock boost level to me.

[Ruergard]

Looks like the car never have been flashed... :vhmmm:

[ttboost]

Did you buy it right from the previous owner or a dealer? Someone owes you an explanation (and a flash) as you bought it with the knowledge that it HAD a flash, no?

[cmore]

Any logical way the car could un-flash itself?

I bought the RS6 from the biggest luxury dealership in town. The previous owner of my RS6 had a bunch of money and put 10k worth of upgrades in the car just before he traded it in on an R8. I didn't have the complete list of upgrades when I bought it, but I was told it had an O.CT chip and Milltek exhaust. I've verified it had everything else, but now it is looking like it is not chipped.

The last piece of the puzzle is to find the name of the previous owner, talk to him and see exactly where it was done. Dealership said it was done at Stratmosphere in New York, but Stratmosphere has no record of my VIN.

Hopefully I can get the guy's name today. Not sure if the dealership will disclose it, but if not I'm not going to be a happy camper.

[ttboost]

Any logical way the car could un-flash itself?

I bought the RS6 from the biggest luxury dealership in town. The previous owner of my RS6 had a bunch of money and put 10k worth of upgrades in the car just before he traded it in on an R8. I didn't have the complete list of upgrades when I bought it, but I was told it had an O.CT chip and Milltek exhaust. I've verified it had everything else, but now it is looking like it is not chipped.

The last piece of the puzzle is to find the name of the previous owner, talk to him and see exactly where it was done. Dealership said it was done at Stratmosphere in New York, but Stratmosphere has no record of my VIN.

Hopefully I can get the guy's name today. Not sure if the dealership will disclose it, but if not I'm not going to be a happy camper.

My guess is: that they will not give you the guys name and they probably flashed it back to stock as they had to "warranty" it and figured whoever bought it would never know... good luck.

[peiserg]

MY guess is that your guess is wrong. unless the dealership put on a ninja suit and snuck into stratmospheres computer to erase the VIN, this car was never chipped. new owner needs to pony up $2500 for his reflash.



My guess is: that they will not give you the guys name and they probably flashed it back to stock as they had to "warranty" it and figured whoever bought it would never know... good luck.

[peiserg]

oh to OP. what are the other upgrades? i put 10k into car........ but that also included water injection kit with install along with oct and full milltek exhaust

[ttboost]

MY guess is that your guess is wrong. unless the dealership put on a ninja suit and snuck into stratmospheres computer to erase the VIN, this car was never chipped. new owner needs to pony up $2500 for his reflash.

Fair enough. :hihi: For the OP's sake, I hope he gets a flash without having to pay for it, as it seems it is owed to him somehow, as that was how the car was represented.

[MaxRS6]

Fair enough. :hihi: For the OP's sake, I hope he gets a flash without having to pay for it, as it seems it is owed to him somehow, as that was how the car was represented.

these sales are usually "as is"- Regardless of what is told orally by the gooey and friendly salesperson (with or without the green horns).

[DHall1]

^^ ditto.

IMHO the days of 2500 reflashes are long gone. Its not that much different to flash a A4 vs the RS6. Your paying for blue sky because the dealers think you can pay for blue sky. You purchased a RS6...you must have money.

I have flashed or tuned dozens of cars over the years and no way would I pay 2500 dollars. .02c

REVO at 650 is more than reasonable. Proven safe. Many have had excellent results and we have a member that is a dealer. Safe4now. I dont make a cent from any sale but when if it comes time to flash my car. He has my business.

[cmore]

I talked to the dealership this morning and they are calling the previous owner to see if they can figure out what is going on. The salesperson says he highly doubts that their techs would have flashed it back stock and he would be upset is this is the case. From talking to him this morning he wants to get to the bottom of this. Also helps that I know most of the car people in town and this isn't a big town. Don't think they want this rolling around town that they misrepresented their car. The manager of the dealership was also involved in the sale of this vehicle and they all knew it hinged on the fact of knowing the upgrades.

This is the list of modifications that were given to me by the dealership:

-O.CT engine chip
-O.CT transmission chip option
-PSS9 Coil over and 9-way adjustable dampers and springs
-Hotchkis sport front and rear sway bars
-K&N air filter
-19"x9" wheels with 255/40/19 tires
-Milltek stainless steel cat-back exhaust systems
-Milltek turbo downpipes with high flow cats
-Hyperboost diverter valves

[MaxRS6]

Good luck and is great that the dealership is trying to assist- that is customer service.

Keep us posted as you hunt it down!

[cmore]

While I am waiting for info from the dealer. Is there a way to tell if it has the O.CT transmission flash?

Also, is the N75 ruled out with this issue? I assume since the requested pretty much equals the actual boost that the N75 is fine. Correct?

Thanks everyone!

[cmore]

Bob from Stratmosphere and I may have an answer to this puzzle. The previous owner put on K&N filters and ran them for about 7 months. As soon as I got the car I re-oiled the K&N filters not knowing they could damage the MAF sensors in our cars. I'm replacing the MAF sensors next week and keeping my fingers crossed! This would explain why it felt faster when I first got it and why even in my VAG-COM pull data that it sometimes went slightly above stock boost.

[DHall1]

I dont think oil on the mafs would cause the ecu to "ask" for a low boost number.

That said, I would take the K/N filters and put them in the little round bin in the corner of the garage. IMHO.

Others may run them without problem. I just dont. .02c

Edit: Nice study ttboost. I like the idea of keeping cylinder walls with a nice crosshatch pattern not grooves up and down.

[ttboost]

I dont think oil on the mafs would cause the ecu to "ask" for a low boost number.

That said, I would take the K/N filters and put them in the little round bin in the corner of the garage. IMHO.

Others may run them without problem. I just dont. .02c


I agree. I have seen many studies, that all but prove that aftermarket air filters offer very little in the way of performance and a lot in the way of poor filtration. I would have to imagine Audi put enough filter in there for 'room to grow". As an example of fine German engineering, my 996tt has 600rwhp with the stock airbox and stock paper filter and stock piping and intercoolers.

Hey..I found one!!! Not 100% scientific, but good enough for me and my experiences.

http://duramax-diesel.com/spicer/index.htm

[xpl0sive]

well considering that OCT told you that its not a simple flash, but a socketed chip, that would eliminate the possibility of the dealership "reflashing" it back to stock... either the PO or the dealership lied about the OCT tune being there, and now they've been caught... good luck getting money out of them

[cmore]

They were wrong, Bob from Stratmosphere confirmed it was a simple flash and he did the car. I feel like I'm shooting in the dark on what this could be and why I'm only running 10-12psi. He said he's seen MAF start going bad and causing a problem like this.

I am getting this code:

17819 - Secondary Air Injection System: Bank 2: Insufficient Flow P1411 - 002 - Lower Limit Exceeded

If I had a vacuum leak and that was effecting the boost of the engine wouldn't see a big difference between requested and actual boost? I would imagine if I had a leak it would say 17psi, but actual would say 10-12psi.

I'm going to try cleaning the MAF sensors, put in stock air filters and go from there.

Chris

[peiserg]

I've had the issue with my car where it somehow reverted to stock and had to have it reflashed by my dealer. Took about 30 mins but well worth it.

Congratulations. you just made $2500 and 120lb feet of torque.

[cmore]

I think I may have found the problem! The vacuum line to the fuel pressure regulator was ripped! I touched it and it fell in half. Replacing it tomorrow and will let everyone know.

[DHall1]

.02c

Dont attempt to try and clean the maf's. Dont use any chemicals on maf sensors.

[cmore]

Ok, some how my boost problem corrected itself on its own! I've been thinking it is the MAFs this whole time, but just couldn't fork out the cost of new sensors. Well maybe the sensors got all of the oil burned off from the old K&N filters, as it looks like I am boosting normal now! Max boost is 14-15psi and it trails off to 12psi near red line. I did notice that the water and oil temp needs to be completely up to temp before it will boost over 12psi.

I did 5-6 pulls from different gears and RPMs and combined all of my results into a single Excel graph with trend line. Sometimes I bump into 15psi, but most of the time it is in the 14s and trails off to 12psi near red line.

if you want to view the Excel file go here: http://drop.io/ksda9c5

[ttboost]

Even this stuff? It doesn't leave a residue. If your MAF is toast, it's toast, but a good spray of this can go a long way...

http://lh4.googleusercontent.com/AhtGAQe_9uzOZlOBkHwh30CL68ikqWj8FJLaXPT-Z9mZJ20opRin6GEBXQF3UvBT-b9CenpVmzbYrc9BQGNVkkncdsKkKBEIKPOBaau1gXj6L-m6YL24maUGzWq6j0RqiyUAFszAcovNEi-aU6XddjQnt_jrwlX7QX3wW41_cnZez5ijc6bNDBQ (http://www.google.com/products?hl=en&q=crc+maf+cleaner&rlz=1R2ADFA_enUS359&um=1&ie=UTF-8&ei=_XVwTNbjCcb_lgfhvLSPDQ&sa=X&oi=product_result_group&ct=image&resnum=1&ved=0CCgQzAMwAA)

[ben916]

... the sensors got all of the oil burned off from the old K&N filters...

Dave, thanks for twisting my arm in NOT getting these.... Where do I send your consulting fee? :)