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View Full Version : Pissed of Lambda/02 sensor?



lswing
June 8th, 2012, 07:56
So I'm running lean with the tune already, the o2's were replaced last year, did I just piss them off or toast them? Drove about 120 miles back country today, got CEL near the end. Gave it the gas a good amount, but no serious flogging. I'm going to bump up the fuel map in the AM, so hoping that was it.

Scan says....

2 Faults Found:
16523 - Oxygen (Lambda) Sensor B1 S2
P0139 - 001 - Response too Slow - MIL ON
16543 - Oxygen (Lambda) Sensor B2 S2
P0159 - 002 - Response too Slow - Intermittent
Readiness: 0000 0000

Justin9212
June 8th, 2012, 14:45
Those 2 codes are the post cat O2 sensors. They are not reading rich, or lean, just catalyst condition. The code means you have an issue with the cats, not the tune.

lswing
June 8th, 2012, 15:29
Thanks, I had been reading a variety of causes. Issue meaning they are not filtering as they should, not enough flow? I was about to remove them a few months back when we had the engine out. I'll read some more, might just code them out. Also the chance of the wires to them getting toasted I believe, causing this code?

4everRS
June 8th, 2012, 15:45
Sounds like it might be precats going bad on you. It could be wires, easy enough to drive up some ramps and check. It also could be that they're bad.

It's a good reason to gut tue precats, but it takes quite a bit of work. Some prefer to do it engine out. Pat and I did mine with the engine in, lowering it down a bit to access the bolts. If you end up breaking one, your dropping the engine anyway though. We were lucky.

Revo should be able to code them out. I guess they're not coded out completely, just less sensitive to the exhaust gas.

Justin9212
June 9th, 2012, 16:32
That code is likely not wiring. I would bank on a cat, or an O2, but more likely a cat.

hahnmgh63
June 9th, 2012, 18:04
It is kind of strange that both codes showed up close to the same time? You have been running your Vagcom regularly so I'm assuming you run it for codes before you do a log. As mentioned the rears just check your Cat efficiency so not a real big deal if the car is running Ok. Do you do emissions testing in OR?

lswing
June 9th, 2012, 21:39
Yep, they weren't there a week ago, got a CEL, scanned and there they were. No emissions here in Lane County. I'm thinking they triggered due to the car running lean, they get the sense there is too much air coming through, don't really know. The car is basically running great, changes a bit due to my messing with the tune right now. I'm overly focused on the acceleration at this point, so mentally it feels like the cats are blocking up and not letting turbos spool earlier, but it's probably just my mind:)

Also, could not get Lemmi to connect yesterday. Hooked up, ignition on, RT intelligent mode disabled, close that (also tried with it running), then could not connect with Lemmi, to read at least, didn't try to flash without a connection from trying to read. Ideas? Was going to add 3% to the fuel map when under load to start.

I cleared the codes and have 120 miles to drive, see if they pop up, but I've also reduced the tune so the fueling is a bit better...