Significance of these codes?

[LIRS6]

Check engine light came on, ran a scan and got following codes:

17863 - Exhaust Gas Temp Sensor 1 (G235): Implausible Signal
P1455 - 008 - Implausible Signal
17865 - Exhaust Gas Temp Sensor 2 (G236): Open or Short to Plus
P1457 - 001 - Upper Limit Exceeded
16502 - Engine Coolant Temp. Sensor (G62): Signal too High
P0118 - 002 - Lower Limit Exceeded - Intermittent
16825 - EVAP Emission Control Sys: Incorrect Flow
P0441 - 002 - Lower Limit Exceeded - Intermittent - MIL ON

Anything significant here? Dealer recently said to expect check engine light to come at some point due O2 sensors, but I figured I'd pass on $3K repair until it's time to change the timing belt

TIA

[Other_Erik]

I don't see an Oxygen sensor code here. EVAP flow on the face of it might concern me since it's setting a MIL ON, but it's intermittent. Coolant Temp Sensor signal too high might mean a bad sensor, might mean it's just gunked up.

The EGT signal (G235/236) are one of three things, in increasing probability:
lowest probablity: exhaust gas temps are sporadically spiking - this would be a problem
medium probability: sensors have gone south after 10 years, R&R them, would be a fairly big job, but I'm not certain you _MUST_ do autopsy table position.
highest probability: There's a known fault with the soldering of the EGT Sensors' thermocouple wiring. Pop open the cover of the sensors themselves and flux out the solder at the thermocouple joint, then resolder them. If your codes don't come back after 50 miles, you've fixed 2 codes for probably 3+ years (or until the sensors actually go bad)


One last piece of advice - If you're going to pore over codes, you really should get yourself a vag-com from rosstech. $300 for a professional-grade code reader / engine programmer on a car like this is a drop in the bucket, and you'll never need to have the stealership pull codes again :)


HTH

O_E

[Bigglezworth]

I had a bad EGT. Mine was showing temps off the map at over 1000deg. In my case the code caused an increase in fuel consumption as my car tried to dump more fuel in to the cylinder to cool down what it believed was high temps in the heads.

[LIRS6]

One last piece of advice - If you're going to pore over codes, you really should get yourself a vag-com from rosstech. $300 for a professional-grade code reader / engine programmer on a car like this is a drop in the bucket, and you'll never need to have the stealership pull codes again :)


HTH

O_E

Thanks yours, curious as to why u would think that I don't have a RossTech vagcom - which is in fact what I have and what produced those codes.... Ah, unless you inferred that the dealer pulled those codes...

[na1mt]

I was able to replace EGT sensors without going to service position.

[Other_Erik]

Thanks yours, curious as to why u would think that I don't have a RossTech vagcom - which is in fact what I have and what produced those codes.... Ah, unless you inferred that the dealer pulled those codes...

'twas in fact what I thought. Glad you've got the right stuff :)

[LIRS6]

Hmmm - ok, now a couple of additional codes (underlined), plus some of the original codes now reading differently :

17861 - Exhaust Gas Temp Sensor 1 (G235)
P1453 - 001 - Open or Short to Plus
17865 - Exhaust Gas Temp Sensor 2 (G236)
P1457 - 001 - Open or Short to Plus
16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 002 - Signal too High - Intermittent
17538 - Fuel Trim; Bank 2 (Mult)
P1130 - 001 - System too Lean - MIL ON
17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 001 - System too Lean - MIL ON
16825 - EVAP Emission Control Sys
P0441 - 002 - Incorrect Flow - MIL ON

Any additional thoughts?

"There's a known fault with the soldering of the EGT Sensors' thermocouple wiring. Pop open the cover of the sensors themselves and flux out the solder at the thermocouple joint, then resolder them. If your codes don't come back after 50 miles, you've fixed 2 codes for probably 3+ years (or until the sensors actually go bad)" thanks - where are the EGT sensors located?

Is it time/prudent to have it serviced?

[Brav]

Many times engine coolant temp sensor can screw a lot of things up. Its pretty cheap, and usually not too hard to replace. Can't remember on this car, but on the 2.7TT takes all of 3 minutes.

Also, likely the EGT solder joints as recommended.

[Other_Erik]

Hmmm - ok, now a couple of additional codes (underlined), plus some of the original codes now reading differently :

17861 - Exhaust Gas Temp Sensor 1 (G235)
P1453 - 001 - Open or Short to Plus
17865 - Exhaust Gas Temp Sensor 2 (G236)
P1457 - 001 - Open or Short to Plus
16502 - Engine Coolant Temp. Sensor (G62)
P0118 - 002 - Signal too High - Intermittent
17538 - Fuel Trim; Bank 2 (Mult)
P1130 - 001 - System too Lean - MIL ON
17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 001 - System too Lean - MIL ON
16825 - EVAP Emission Control Sys
P0441 - 002 - Incorrect Flow - MIL ON

Any additional thoughts?

"There's a known fault with the soldering of the EGT Sensors' thermocouple wiring. Pop open the cover of the sensors themselves and flux out the solder at the thermocouple joint, then resolder them. If your codes don't come back after 50 miles, you've fixed 2 codes for probably 3+ years (or until the sensors actually go bad)" thanks - where are the EGT sensors located?

Is it time/prudent to have it serviced?

I can't speak to the P1130/1128, but if it's reading lean, it -could- still be connected to bad temp readings, but the fact that it's not saying intermittent would have me just a bit worried (probably over nothing).

The EGT sensors themselves are bolted to the firewall behind the engine, not exactly impossible to reach, but the thermocouple gets routed down and in, so any work you do on them is going to be under the hood rather than at a nice workbench. Look for a Brown plastic box about 1.5x2.5 inches, maybe an inch thick, bolted onto the firewall. Going to see if I can find the writeup for locating/removing to give you an idea...

Here's what it looks like:
http://www.ebay.com/itm/RS6-EGT-sensor-kit-Genuine-Audi-2003-to-2005-077998124-/251411636682?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a894d21ca
(the darker one may have faded to a lighter gray color)

Here's what needs fixing (if this is the problem)
http://www.audi-forums.com/c5-forum/61127-quick-egt-sensor-fix.html