So, i did the doide mod, have boost set to 14psi on one and 17 psi on another setting. I sometimes throw a check engine light no matter what boost setting. I have a stock FPR on my 01 black a4. The only code it throws is a P0171, witch is: system to lean bank 1. That is thelast cylinder on the fuel rail. I'm wondering if it would be a good idea to upgrade the FPR so the system doesn't go lean, unless you guys think its a lazy injector or somethings else. My MASS AIR sensor is clean as a whistle too. What is the stock FPR on this car anyways?

 

seafoam your car and get the MAF tested. clean your 02 sensors with intake cleaner too.

 

seafoam???what is that

 

Its like a cleaner you can put throught the engine. No, you dont need a higher fpr, 17psi isnt high enough. You should check the vac line to the fpr however, its a known leak point and could throw that code

 

i put a new vac hose on the fpr line already. It kinda feels like at boost the car wants more of something but not getting it all of the way. I tried to take off the o2 sensor, yeh right. going to try that again when I have time so I can spray it down. The car already had a 44k treatment before I bought it, so I don't think that it needs anything like that yet. I also have run 2 bottles of fuel cleanerthrough 2 tanks of gas init when the light first came on. I still seem a little fishy about the whole fuel system being able to keep up with the boost that i'm throwing at it. Other boosted cars usually need fuel upgrades when you toss more boost their way to keep a proper A/F. You guys say that these little injectors and small fpr keeps up?????

 

I run 20psi for well over a year and im on the stock fpr. You are having a problem, but its not diode related. The stock injectors are good for 230-240hp and then 20-25hp more with a 5bar.

 

20psi from a k04 w/ stock fpr all day over here. a k03 is TINY, 20 psi out of that thing is nothing compared to 20psi out of "real" turbos

 

So any ideas on what it is? or what to check? I'm stumped

 

even though your maf looks clean, doesn't mean it is........ and the housing could be imaculate, but it is the plastic piece with the metal wires that is what goes bad


mine looked fine too, but went bad

 

I've sprayed it clean very recently