I have a 2002 S4 with many unknown mods done that I bought in Colorado last September. I moved to SoCal in January and she has given me nothing but greif ever since.

The biggest problem seemed to be an altitude adjustment...I noticed almost immidiately that it was eating fuel big time! First to go out and replaced was the O2 sensors and then I had to get the ECU pulled out and re-chipped. The original chip upgrade in her was supposedly done in Germany according to the folks at GIAC and their software could not go over it so the whole ECU was shipped to them and re-done.

This seemed to help for a while but about a month ago while city driving at normal speed, all the warning lights lit up (ECU, Traction, ABS, Check Engine) and of course the serious loss of power that goes with that. I also lost all power to my boost gauge. I was close to home and so I stopped for a bit and left her sit. After a couple hours I got back in and she ran fine, the only light remaining was the check engine. I then drove straight to my repair shop and they pulled the codes. I was told that there were a couple but were all related to throttle body issues and they found the boost gauge was poorly installed and therefore thought that it was likely a short from the guage and that it probably just momentarily "freaked out." They cleared the codes and we moved on.

She went for about a week before I had the same problem again. Weird thing was that it was very intermittent and seemed to only happen in the morning and never the afternoon/evening. I was always able to shut her down for a moment and then restart and the ECU light would shut off and she would run as normal. Sometimes the ABS & Traction lights would stay on with the check engine, of course. After only a week of that, I went to leave one Sunday to leave and she wouldnt start at all. I had her towed to my shop the next day and they pulled all the same throttle body codes and with a 3 step to the gas peddle, they were able to get her started. It was then suggested that I go ahead and replace the throttle body. We looked into new throttle body for 8 bills, a little out of my range at present. I continued to drive her only to work and back (20 miles/day) while I looked for and finally did locate a used one with supposedly only 37K on it.

Exactly one week later, I get the replacement throttle body and on the day I am going to change it out, she literally completely freaks..all the warning lights again and virtually NO throttle response. I changed out the throttle body right then and started her back up...she ran fine for like 90 seconds and then sputters with the same lack of throttle response as before.

I love this car but its KILLING me...sorry for the book here but I figured more details the better. Any suggestions would be appreciated.

 

first of all make sure its operating properly. remove the boot, turn the key on and exercise the accelerator pedal. if its all working properly and the blade doesnt get hung up on anything, you need to get vagcom on it and relearn the throttle position. not exactly sure how to do that or what test to go into. .but id start there..

 

Sounds to me like your computer might be a little screwy. Have you disconnected the battery since you moved? Might not do anything but it might reset it and "relearn" the ambient conditions or something...

 

So today, after sitting all alone in the parking lot through the weekend; it started and ran jnust fine. I drove it the 10 miles home with no troubles!?!?!?!?!??!?! What the hell?!

 

..typical throttle body issues.. next time you have some problems, remove the boot and spray carb cleaner in there at the blade pivot points... those have a tendacy to bind up and stick with carbon build up..

btw, i have a used good throttle body for sell, pm me if your interested..