05allroad

I was driving home on Saturday night when my check engine light came on. I called a friend with a VAGCOM yesterday who helped me pull the codes (many!) and I have been searching to try to determine the cause(s). I'll pasting the codes below along with the description and some guesses as to what could be causing each code based on my searches - any guidance or insight would be greatly appreciated! There seems to be a common theme as most codes seem to point to Vacuum leak, MAF, O2 or EVAP issues. I'm scheduled to have the coil pack recall performed tomorrow which may be the cause of the random misfires on cyl 6?

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Code - Possible Cause

Description of code
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P1557 - Boost Leak?

(static) Turbo boost sensor (A) circuit value above upper control limit

P1139 - Clean MAF or EVAP can purge valve?

(intermittent) Long term fuel trim add. fuel bank 2 system too rich

P0175 - MAF? Air Filter? Clogged suction jet pump?

(static) Fuel trim, bank 2 System too rich

P1137 - O2? MAF? EVAP purge valve?

(intermittent) Long term fuel trim add. fuel bank 1 system too rich

P0172 - MAF? Air Filter? Clogged suction jet pump?

(static) Fuel trim, bank 1 System too rich

P0300 - Upstream or Downstream 02? Coil packs?

(intermittent) Random/Multiple cylinder misfire detected

P0306 - Fuel filter or coil packs?

(intermittent) Cyl 6 misfire detected

P1602 - Weak battery?

(intermittent) Power supply terminal 30 Low Voltage

P0455 - Gas cap?

(static) EVAP emission control system (Gross Leak) Leak detected

P1127 - Vacuum leak or MAF?

(intermittent) Long term fuel trim mult Bank 1 system too rich

P1129 - Vacuum leak or MAF?

(intermittent) Long term fuel trim mult Bank 2 system too rich

05allroad

I've gotten a few PM's suggesting that many of these issues can also be the result of a torn TBB.

Thanks in advance for any advice or suggestions.

05allroad

A TSB was performed to fix the airbag fault (coming from drivers seat after moving the seat) and the hazard relay has hopefully addressed the left turn signal issue.

Looking like most of the codes were easily addressed, but they're still seeing the Gross EVAP leak and the turbo boost sensor issue now. They're going to smoke test it for leaks & I'm still hoping for a cheap & easy fix!

Anyone been in a similar situation an have an idea wat I can expect?

Pete@ECSTuning

In these situations it sometimes is best to clear/rescan so see what codes come back. Sometimes they come back one at a time instead of assaulting you with a whole list. If you have it at a shop already, a boost leak test would be a great place to start. All these rich conditions sound like they could be related to a boost leak.

05allroad

Thanks, Chris - appreciate the input.

They did a smoke test this afternoon & I should get a call with the results & diagnosis shortly.

Rob Swift

I have the codes 1127 and 1129 on my audi a6 2.7. Can anyone tell me the bottom line is it the o2 sensors in the front or maf sensor. Need real help.

silverd2

Not the 02 sensors...more likely your MAF...or even the rubber Y-boot on the throttle body, for which Audi issued a TSB years back, for cracks allowing boost leak leading to rich condition and producing exactly those codes.