hello, I have an 98 a4 quad avant 2.8 trip auto, lately I have had some issues w/ the car bucking in 4 and 5 gear sometimes in 3rd when I hold the throttle at a steady pace the rpms go up and down and the bucking happens no issues from a dead stop gears 1 & 2 but the others is when this happens is this a trans issue or another issue I changed the plugs and it still happens I also took it to advance auto & auto zone for a code read and both times the scanner would not connect to the car Any help is appreciated. Thanks

 

Another member had stated on another thread if you have an aftermarket radio installed you might need to disconnect in order to plug up a OBD-2 device to the car.

I don't know if its transmission related, but hopefully not. If it is, your looking into a big investment. If its not, you will probably get by replacing a sensor or solenoid here and there.

 

yes kamil it does have an aftermarket radio i'll look for that thread thanks.

 

Disconnect the radio first. A improperly installed radio will fry a scan tool. It sends power to the communication line.