Coked up Engine?

[DrGold]

Dear All,

The following codes were logged approx 500 miles ago, Audi did the diagnostics which indicated both ECUs were faulty. This being extremely unlikey, Audi technical advised updating to new 0090 software (from 0080). Car ran fine for next 500 odd miles.


17819/P1411/005137
Secondary Air Injection System; Bank 2: Insufficient Flow

18265/P1857/006231
Load Signal: Error Message from ECU

18619/P2187/008583
Bank 1; System too Lean at Idle

17796/P1388/005000
Control Module Malfunction - DBW Throttle Monitoring

After 500 miles, have now got the emisions light on with the following:

00369/P0171
Bank 1; Fuel trim - system too lean; intermitent

Car now booked to go back in. Anyone have any ideas on this? appreciate not an easy one - Audi (Stansted) don't seem to know what's going on. Tech did say they had just finished de-coking another RS4 - anyone on here?

Thanks

Mark

[adsgreen]

I'd check the vacuum and air intake lines.
O2 and MAF sensors might be worth looking at too.

[P_G]

Looks like three potential issues and none linked to 'coking' Like adsgreen says, check MAF and lambda/O2 sensor, vacuum system and the sensor on the DBW throttle body. Coking is only on the IM and valve seats so nowhere near any of the afore mentioned.

[ArthurPE]

I'm with P_G, my fist WAG is the TB sensor
that would account for mixture and a bad load calculation

[DrGold]

Many thanks for the replies - much appreciated.

I'll forward on to the garage.

[adsgreen]

Cokin could hinder the mnifld flaps and restrict airflow if they are stuck in "tumble" position but I know from experience that you get a pretty specific error code and EPS light on instantly.
But yes - TB sensor is a good place to start there.

[P_G]

Indeed, that would be a P2015 +/-1 or P2020 +/-1 code IIRC because the runner sensor would pick up an implausible signal on the angle of the flaps.