I have a 1999 A4 1.8T. The car has a stage 1 chip upgrade from APR. I recently noticed that the car misses or stumbles under near to full boost. The ECU never puts up a code so I'm not sure what the problem could be. Other wise the car runs great with no issues. The car has about 210,000 miles and has been dead reliable.

If anyone has any suggestions or answers I would greatly appreciate it.