SIR VBall

whenever I fill up with 100 octane gas, I get 17536/17538 errors in my 2000 S4 ECU. This means left bank and right bank are too lean. I checked the ECU, all high pressure hoses, diverter valves, TBB, etc. I have no way to test for other leaks, MAF or possibly bad injector. Is it possible with the APR 100 octane chip that I'm not getting enough fuel? Anyone else getting this error?

On an aside, this only started happening since my dealer replaced the valley pan gasket since it was leaking oil all over the place. I had the dealer look at it, but they couldn't duplicate the error with the stock ECU, but I fired up 100 octane race program and up flipped the errors.

John CC

MTM has a FPR in their stage 3 kit. Do you have downpipes and straight pipes? If you do, your car is probably pushing close to 370HP with race gas. I am not positive on this, but you might be pushing the capacity of your fuel system.

Having said that, I never had that happen to me. You should also post this in the S4 forum as there are at least 10 people with race program and downpipes. You definitely do not want to run lean !!!

monkey2

i agree with what johnn cc said, running lean can put holes in the top of your pistons, and with all your mods, it'd be hard to get audi to cover that under warranty! how much is an engine? It'd be easier to get another s4! I do know the 5v-v6 co$t$ $20,000! how high does your boost get?

BOOSTD

Are you sure you're running out ALL the premium before switching to the 100 octane program? Granted our setups are quite different, but I ran on '0' miles til empty for about 15 miles, filled up on 100, drove another 20 miles and switched to the stage III race program; I <b>still</b> had some 93 in the fuel delivery system, as I didn't feel anything different with the car. Another 20 miles later and the car turned into a beast (no DTCs though).
2nd: when are you getting the Check Engine light? Immediately after switching to the race program, or after extended driving?

carace

running the 100 to get the most out of the current setup?

John CC

APR has 100 Octane program with advanced timing etc. Adds around 15HP and improves trottle response

John CC

Do you have to modify ECU Code when you up the FPR pressure?

The R

the higher octane gas running thru your fuel system before running the race program? Not saying there isn't something else wrong, but you need to make sure you enough race gas as well as it running thru the lines before switching to that program. I like running higher than 100...try running 104 or 105 atleast.

I hope you don't have a problem. Let us know what you find out.