noprndlhere

Long time member, seldom poster.

I did some searching, but I don't know what keywords to use for searching nor did I find anything that directly got me what I might need.

The car is an '00 manual, 48k miles. APR chip with std, performance and valet modes. No other engine related mods. I've owned since new.

When accelerating with either std program or performance mode - I don't feel the performance seems to be any different as it once was. The throttle response differs slightly, but the force of acceleration and resulting time to 70mph seems no different. It just seems to lack that umph!

Any ideas where to look?

I was thinking that one of the intake "hoses" (perhaps the Y hose) is split? Any good pics and procedures to lead me through that process?

Or should I be looking at something else? Such as the blow-off valve? (I must admit, and am embarrased to say - I have no idea where to find it.)

TIA for your help. I posted in the S4 forum also.

Craig

quickaudi:STFA

also, have someone replace your spark plugs and diverter valves. may also have a torn throttle body boot or f-hose. have Someone check your codes for bad oxygen or EGT sensors

noprndlhere

F-hose?

What should be done first, or do everything? I'd prefer to do it myself, but I don't know where to start. I'm mechanically inclined, I just don't know these systems other than the concepts. (I have installed superchargers all by myself, but I knew what parts were what and could follow detailed instructions).

Where are the diverter valves? What do they look like? Any pictures somewhere?

Or are you basically telling me to take it to the dealer? I'd rather not, as the whole scheduling thing is a @&!% pain. They will want to replace faulty parts with oem, and I'd rather upgrade if reasonably possible.

The check engine light is NOT lit, nor is there any other indication of trouble. I do not "know" anyone with a VAG.

quickaudi:STFA

I suggest a full-on use of the search function. Limit your results to the B5 S4 forum. Since my car is a '01.5, I don't know exactly where the f-hose is on your car. The diverter valves are near where the Y-pipe splits and goes down the front of the engine. Search for pictures.

Take it to an independent mechanic that you trust. He can scan your codes as well. Buy a VAGCOM. It's worth it.

PSYC0TIC ONE (USMC)

2nd on EGT sensors... that was my problem, (driver side too, major PITA for DIY)