Code P0171 and P0300,P0301,P0302,P0304 [Archive] - Audi Forums

: Code P0171 and P0300,P0301,P0302,P0304

07-23-2011, 09:57 PM
Hi! I have a 03' audi A4 1.8T FWD. engine light on. I did put the scanner to it and give me a code P0171 Bank 1 System too lean.
1. MAF sensor
2. Vacuums lines
3. Breather regulater valve
4. Fuel injector Oring
5. Crankcase breather
6. Suction jet valve
I did erase code, the car get worse but only at idles.
Above 5mph runs fine.
Later the same day engine light come on put scan on it and give me P0300,P0301,P0302,P0304 miss fireing in cylinder 1,2,4,
Now I dont know what to look for MAF or coil?
Any idea? Thanks!

07-28-2011, 11:05 PM
dont worry helping me. I did find the problem. no more idle problem.

Sergry vataman
10-20-2011, 11:58 AM
Hey I got the same codes this morning , but only the fourth cylinder misfire. What did you duo to fix this?

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10-20-2011, 07:03 PM
Hi! If u have an idle problem in your 1.8T u need to check the vacuum system.any crak in the hoose or the valve can cause idle issues. in my case non return valve part# old:06A133528A,new #:06A133528D ,Audi dealer $59, VW dealer $51, but u can ask the local auto parts store to get it from dealer and u can save money.That what I did I payd $45 for it at Orileys.
2.spark plug wires
3. coil.
all this can cause code:P0171 and P0300,P0301,P0302,P0304 to come up on the scan. good luck let me know how it went.

Sergry vataman
10-20-2011, 08:43 PM
Thats the funny part the idle is smooth and there is not lag no lean or anything, but I changed the spark plugs last week and on monday I put on a k&n come filter. And today is when it popped up, but thank you. I will let you know how this goes.

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Sergry vataman
11-01-2011, 12:29 PM
It was a vaccine line.

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11-15-2011, 11:02 PM
Thanks for the reply! Good job!

10-31-2014, 11:31 PM
Thx for parts #