Does anyone have a permanent fix (as permanent as fixes are with Audis) or upgrade for the emissions control fiasco of my 2001.5 Audi S4 2.7t? I have replaced all manner of hoses, secondary air injection pump, catalytic converter, O2 sensors, and the like. I can remember one episode where the check engine light did not come on for over six months, but that is a distant memory.

My current history: When it is cold, I get codes 1111 and 1147. Could that be high octane fuel at high altitute (Colorado)? Recently, however, I have been getting codes 1136, 1138 and 1476. I get a misfire when I reset the check engine light (so don't clear the check engine light). The car otherwise runs well, but I do have low fuel mileage.

I assume I have some sort of air leak or disconnected hose that is letting air into the vaccuum system.

Does replacing all the vaccuum hoses with higher quality hoses slow down the deterioration of this system over time? Any brands you would suggest? Any kits you think might be a good upgrade?

I am headed to the mechanic (again) to try to figure this out and nurse this POS, which I love, back to health. I would welcome any advice or commiseration.

 

You could always get a tune from J-Fonz tuning in which the 02s and EGTs are coded out, mine are. I doubt the fuel is the problem.

I like AF but for the B5 S4 there is just way more info on Audizine.com. Run your codes through the search there and see what comes up. If that doesn't help go to 3zero3 Motorsports in Wheat Ridge, they are top notch.

 

Sounds to me like the rubber "Y" pipe in front of the throttle valve where the two plastic boost pipes in the front of the engine meat, is cracked on the bottom side and causing your issues. This was a notorious *** kicker for many techs for a long time and often overlooked for fuel, boost, and cat faults. If the underside of the Y pipe turns of the be cracked/torn make sure you lightly file your throttle valve connection points to prevent the tare from happening again.

 

I will look into the sites and fixes you suggest. Thank you.

 

I'm starting to think the CEL is just another OOOO feature. Mine goes on between 30-200 miles because of cat warm up issues, even though both cats have been replaced. I am at the point where I will apply a small circle of black electrical tape to the instrument panel over the CEL. That's the only permanent fix and if it starts flashing, you can still see it (at least at night).