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.