turbo-tonyinatlanta

I have a 99 A4 1.8T that I just installed a GIAC chip to the ECU this afternoon. The car seems to drop the idle pretty low when you come to a start but not low enough to kill the engine. After about an hour of driving around I came to a stop light and the idle really dropped low and idled extremely rough, then the check engine light came on and stays on now after I turned the car off and back on. Anyone seen this happen before? Should I be very concerned about the light? Unfortunately I can't get the car back to mechanic til Tues. Is it safe to drive till then?

paul_858

see your mechanic, or you can check to make sure the chip is sitting flush.. another thing to make sure to do is when you re-installed the ecu, you turn the key on, but not the ignition, dont' start the car basically.. this allows the ecu to do a throttle body adaptation to make sure the throttle body and ecu talks correctly. That's probably your problem if you just plugged the ECU in and quickly started the car back up. Go ahead, disconnect the ecu again, reconnect it, turn the key to the on position without starting the engine, you should hear a high pitch sound coming from the engine bay, takes about 1 minute to complete, adn then you'll be able to start the car, try that =) GOOD LUCK! if all else fails try going back to the stock chip, or contact a local audi-er with a vag-com

turbo-tonyinatlanta

The light flashed first for maybe 20-30 sec then went to solid lit light

AEB_Head

VAG the car if you can and read the Codes.
do throttle adapt 060 on that car
check your plugs.

turbo-tonyinatlanta

I don't have a VAG, not sure what throttle adapt 060 means. Should I be concerned otherwise about the light being on? I am definately going to take my car back to tuner who installed the chip on Tue(they're closed Sun & Mon). But do you think the car is safe to drive til then with the light on?

Sourdough Josh

1. Disconnecting the ECU entirely (so it gets no power) for a couple minutes.

2. Reconnect the ECU, and turn the key to the ON, but NOT start position. Leave the car on (again, NOT with the engine running, just power) for a couple minutes. I can't remember the exact figure, but 5 or 10 will definitely be enough

Now, turn the car on and drive around. See if that fixes it.

If the light is flashing, it's not good to drive the car. If it's solid, and doesn't flash, and you don't feel that roughness, you can drive it to the dealer, but still I wouldn't recommend driving it around town.

Good luck!