Yeh, autozone would be the last place to take it to read codes for this. A generic OBDII code reader can't read the "hidden" codes that cause "soft limp" or no limp at all. You need to run a motis scanner or a vag or something similar to get those "hidden" codes that don't throw cel. Those codes sometimes tell more of what you need to know. For instance, someone unplug your n75 and run it for a while. Car won't throw a cel with it unplugged. But if you use a vag for instance, and run a code retrevial, a code will show up on it saying that the n75 is unplugged or not functioning.

 

I still think that you should test your injectors for a lazy one. It might be over heating.

 

I thought autozone used a Modis???? Guess not, yeah those Modis' are the ****

 

you know, wouldn't hurt to check fpr either, 3 and 4 are at the end of the rail. could be starving for fuel.

 

I've never seen an autozone use a modis.........always a cheap generic one

 

Thats weird cause my A4 been doing the same thing to me too. I have a VAG OBD II reader and it keeps popping up with a "17536 Fuel Trim: Bank 1 (system too lean) p1128". This popped up after i fitted it with a carbino intake, and when i put the stock box back in the car still throws me a lean code. I got the intake from my friend who gave it to me cause he wrecked his a4. The code keeps poping up and its driving me mad cause it makes me run at safety boost or "limp mode". It also for a while before i cleaned the MAF gave me a "16891 Idle Control System RPM: Higher than Expected". any thoughts anyone? O i have a 2001 A4 1.8t Quattro 5-speed Stick.

 

i get codes from this whether or not the CEL is on. it reads them, and i know what running lean is. i have been hunting this problem for a while

Also, the temp guage never fully hits the middle, allways just before it or farther, which could imply running ritch. (lean runs hot rich runs cold)

also, the exaust pipe has a fair bit of carbon in it, again would imply rich.

Looking at those, my best guess is still the secondary air injection as it could make the CAT think its too lean and the computer will try and compensate by adding more fuel, giving me the carboned exhaust, the running cold, and the missfires.