CEL - System Too Lean (P1136)

[A4orce84]

Hey Everyone,

So I've had this CEL for a while (P1136 code) and I've searched and tried a few things to fix it.

Background:
99.5 Audi A4 1.8Tizzle, had a busted catalytic converter that gave the same code when it popped out of it's flange. I jerry-rigged it so it would stay connected, and after that the CEL went out. Installed a Labree HFC and a few days later the CEL popped back up.

Symptoms:

Car idle's a bit funny when in park/neutral, in drive everything seems fine. My gas mileage has been crap, and sometimes the car hesitates when accelerating WOT.

Solutions Tried:

Searching around it seemed that a lot of the "potential" issues were with either the MAF or front-o2 sensor. I cleaned the MAF and replaced the O2 sensor..........all symptoms still persist unfortunately.


Anyone have any other ideas what it may be? I might break-down and taking it to the local Audi Dealership here since I don't want to keep guessing/buying new parts. Thanks in advance everyone!

--Asif

[ct1.8t4me]

Have you done a throttle body adaptation? Also check for vacuum leaks. Do you have a boost/vac gauge?

[A4orce84]

I do have a boost gauge, vaccum is right where it needs to be. I haven't done a TBA....but I don't think that would account for such horrible gas mileage...

[A4orce84]

bump