AKS4

OK, apologize for the n00bness yet again, but this car is baffling me. I won't bore you all wiht a 3 page story of driving to Jamie's house then getting codes, and yada yada. Those that have followed my threads know that my car has been throwing codes indicating boost leak, O2 sensor and coolant temp sensor. Sooo, If someone or a few of you coudl give opinions on what could be wrong, that'd be great. Heres a time line of the codes and what I did afterwards.

Late December, CODES: O2 resistnace too high, charge press exceeded and MAF too high. So searched the forums, *could be a MAF or boost leak, so cleared codes and checked for leaks, none apparent on TBB and F-Hose.

Early Jan, CODES: Charge pressure exceeded. Made pressure tester and checked for boost leaks. Found left intercooler hose loose. cleared codes.

Mid Jan, CODES: Charge pressure exceeded and O2 resistance too high. Searched forums, found it could be a bad MAF, but check flow and O2 sensor. Cleared codes and Logged 030, 032, 115 and 211. Pointed towards O2 sensor, but possibly still MAF

Day later got CEL, CODES: O2 sensor resistance, Fuel trim banks 1 & 2 too lean. Checked forums/posted, still could be MAF, but with the O2 popping up, should replace it. cleared codes.

Next day another CEL, CODES: Random/multiple misfire, Cyl 1&4 misfires, O2. Checked forums/posted. sounds like bad O2 and replace coolant temp sensor. Cleared codes.

Last night Got another CEL, and what smelt like burnt coolant/rubber/belts, CODES: Fuel trim banks 1&2, charge pressure exceeded. Checked engine, FPR was off Y-pipe. (I haven't a clue how, maybe not shoved on tight after last pressure test) cleared codes and went for drive see what other codes could pop up.

Last CODES: charge pressure exceeded.

SOOOOOOOOoo, in the Audiworlds humble opinon, after checking for boost leaks and finding only the one, Does it sound like I should replace my MAF before the O2 sensor? Would the FPR off the y-pipe cause me to have misfire and fuel trim codes? would that also effect my O2 sensor readings giving me resistance too high? I know eventually I should replace them all, but to solve my immediate issues is it as simple as the FPR got blown off and I have a failing MAF? Opinions would be reatly helpful.

TIA

DAP@EPL

FPR line doesn't connect to the y-pipe. That's the PCV line for oil blowby/crankcase ventillation.

Have you replaced anything yet or do you just keep checking and clearing codes?

-Dave Pramanik

RKA

PCV or FPR? The FPR has a small vac hose attached to it.

Have you checked the BPV's to make sure they aren't faulty/leaking?

AKS4

Well I guess it was mainly why has the charge pressure returned?.....

DAP@EPL

Fix one problem at a time. You definitely have a faulty O2 sensor. Replace that and then see what codes return.

-Dave Pramanik

AKS4

And I have the O2 sensors in hand, hooking up with friend tonight to borrow O2 socket and extension. I was merely wondering why the Charge pressure code returned and the O2 seemingly disappeared.

Sooo, I have yet to replace the O2 and coolant sensors. I haven't been ***** nilly clearing the codes either however. After each scan/problem I searched the forum, some were ones people logged blocks and cleared to see if they'd return, others pointed to my O2, and a possible MAF. The only ones commonly returning was the intermittant O2 and the possible failing MAF codes. Only this week was confrimed I need an O2, curious if I also need a MAF.

Sorry for the n00bness. But being so far removed from the US up here, would like to make sure I need to replace something, because of cost of shipping, and I don't have any other Audi Tuners. My bad..

DAP@EPL

rather than trying to diagnose a whole slew of codes at once. Make a fix and see what codes return. Repeat until all issues are resolved.

-Dave Pramanik

RKA

There is some kind of boost leak present. I would deal with that first. Some boost leaks can result in lean/rich conditions.

Regarding the O2 sensor...a lean/rich condition can also cause the sensor to go outside it's specified range, however that's not what's happening here. It sounds like the O2 sensor is toast, and the issue is probably (but not definitely) independent of the boost, lean and misfire codes. If this is a sensor 1, I would not mess around with it...just replace the sensor. If it's one of the "sensor 2" errors, that's just an emissions check. I wouldn't concern yourself with that for now. Fix at your convenience. It won't affect the way the car runs, it just trips the CEL.

Your boost issue and lean issue should be considered critical. Focus on the boost first.

AKS4

Yeah, I guees I was trying to solve EVERYTHING at once, and that isn't going to happen. I have checked the boost issue last weekend, but at the time found on ly the one loose intercooler pipe. We checked, cleaned and tightened the other side.

I am replacing O2 this weekend, as I said got the sensor from the stealer yesterday after confirmation of the VW part working.

Again, I thank you guys and this forum a ton.