# Need help w/ P1176 & further diagnosis



## amper (Jun 27, 2000)

I have a problem with my wife's Jetta, which has recently failed inspection for emissions reasons. Last week, I successfully diagnosed and replaced a bad MAF sensor which was giving me the typical "Fuel Trim Too Lean" DTC, as well as replacing the DV, which was fluttering a bit.
After a week of driving the car, the CEL came back on, and yesterday's scan revealed the following DTC:
VAG-COM Version: Release 607.3-UD
Control Module Part Number: 06A 906 032 DM
Component and/or Version: 1.8L R4/5VT G 0002
Software Coding: 07530
Work Shop Code: WSC 00066
1 Fault Found:
17584 - Bank1: O2 (Lambda) Correction Behind Catalyst: Control Limit Reached
P1176 - 35-00 - -
Readiness: 0000 1000
Now, going through the Measuring Blocks, the only thing that seemed out of place was one reading in Group 037. The "Lambda Regulator Dwell Period" was measured as -0.031. According to the label file, it would seem that the specified range for this value is -0.02 <--> 0.02 ms. Otherwise, the computer says that both O2 sensors pass their tests, so I'm confused as to what the problem really is.
From what I have been able to gather in my searches of VWvortex so far, it seems that I need to do further diagnosis of both O2 sensors and the catalyst to pin down the true source of the problem, but I haven't found any documentation of the testing procedures. It would also seem from my searches that this may be a relatively common problem, so I'm surprised not to find more documentation.
Can anyone help me out here? Incidentally, the specs of the car may be in my .sig, but it's a 2001 Jetta GLS 1.8T Sedan with an AWW engine and the four-speed non-tiptronic automatic transmission.


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## amper (Jun 27, 2000)

*Re: Need help w/ P1176 & further diagnosis (amper)*

Bump.


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## Uwe (Jan 16, 2000)

*Re: Need help w/ P1176 & further diagnosis (amper)*

A summary of what Bentley has to say on this:
Check oxygen sensor aging oxygen sensor after catalyst.
- Coolant temp at least 80C.
- Basic Settings, Group 043.
- Run engine at 1800-2200 rpm and maintain until field 4 goes to "Test On". Cat temp in field 2 must be at least 300C. Eventually it will either tell you that the sensor is OK or not. If not:
-Road test vehicle to free oxygen sensor of possible residues and repeat test. In other words, drive it like you stole it for a while.
If none of this works, replace the sensor.
-Uwe-


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## amper (Jun 27, 2000)

*Re: Need help w/ P1176 & further diagnosis (Uwe)*

Thanks for the reply, Uwe.
I finall got the Jetta back from my wife yesterday. The first time I ran the test, it failed. Then I cleared the DTC's and re-tested OK.
I've been driving around like a maniac all over NJ and PA for the last two days (I-195 from the PA Tpke to Reading and back is a fun ride!), and managed to get the cat heated up to 800-825 deg. C. The Group 037 "Lambda Regulator Dwell Period" seems to be holdng pretty steady at -0.008 to -0.012 ms.
All readiness tests have passed, and no more DTCs have appeared, so I guess it's off to the inspection station.
I suspect that running for so long with a bad MAF gunked up the works, and it just needed a bit of time and flogging to clear out the cat and sensors.


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## bdsxxx (Dec 30, 1999)

just curious you indicated the cat was 800 deg, is this normal, thought I saw 350 to 500 in VAG display.


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## [email protected] Parts (Nov 27, 2006)

Where is your scan?


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