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Discussion Starter #1
About 2 weeks ago I started getting CELs every day or 2. The first fault was during bitter cold so I just cleared them useing the clear fault feature of the APR programming. After the third CEL, I checked with the VAG=COM. The fault codes I have in are individual cylinder misfires (all), random misfires, fuel trim too rich and O2 sensor heating too low. After clearing the fault codes and using the VAG-COM engine module readiness check fails or is incomplete for O2 sensor heating, O2 sensor, Secondary air injection, Evap emissions, and Cat converter. About 150 miles before the first CEL I had a new battery put in and the origional N75 valve reinstalled. Other symptoms include a stumbling idle, occasional backfire when letting off the gas, and occasional stall when down shifting and foot is off the gas. Does anyone have a guess what is causing this?

The car is a 2001 1.8T 5 speed with APR stage 3 turbo and programming installed. Prior to the shop visit where the transmission work, battery and N75 work was done, I had no CELs since the APR kit was installed.

Thanks for your help. Ray
 

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I wouldn't worry about the readiness, unless you manually ran all the readiness tests. Randomly taking a look at them does not assure that the test has ran, so you get many false negatives. I'll list the test instructions below to runn all the readiness tests.

Sounds like an ICM failure. Other's can more accurately tell you how to diagnose that. It's possible that the too rich, and low O2 heating are due to the unburned gas from many misfires.

From Uwe Ross of Ross-Tech:

When you clear DTCs (be there any or not), everything gets reset. The
readiness codes will set themselves in a few days on their own. But if you
want to bond with your car, here is how you do it...

Fire the engine up, let it idle... all steps will be done in "Basic Settings
- 04".

071, idle, EVAP testing I think
034, idle - 3000RPMs. Pre cat O2 testing. (cat must be up to temp)
035, (Pre cat 02 for bank 2 on V6)
036, idle - 3000RPMs. Post cat O2 testing. (cat must be up to temp)
037 (Post cat O2 for bank 1 on V6)
046, 2800 - 3000RPMs. Cat testing.
047 (Cat for bank 2 on V6)
077, idle. Sec air injection system testing
070, idle. can't remember

Setting readiness codes are pretty much the same for the 2.0, 1.8 and 2.8L VW engines on the. The RPM range can vary. Also, I find it best to test in the order given. Trying to set 046 before 034 and you will be sitting there for a long time.


As far as finding the proper idle for the test (O2 sensor for example) you have to start the test with the VAGCOM, and then slowly raise the RPM until the VAG indicates that the test has initiated... then hold it there. For the V6 the cat testing is between 2750 and 3200 rpm so the reanges do vary.
 

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Discussion Starter #3
Thanks for the information on the engine readiness tests. You are correct, I did not use the proper procedure. I just saw the button there and thought I would run it (and was suprised when it showed so many failures). Anyway, could dirty plugs cause this problem? I was told that this could be the cause. Thanks again, Ray
 

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Did you check the ICM as Pass-Variant suggested? Flashing CEL, very rough idle, shaking that smoothed out a bit at moderate speeds were signs that my ICM was dying.
 
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