99 Z/34

Hi my car is acting up the car runs fine but get going anywhere for a while. after you stop and get going again the car doesnt want to shift into second, or if you stop for gas and try to start it, it take a couple of times to get going, or if you step on it when the motor gets to 4000 pm it doesn't want to rev any higher.

SES light on? I want to say clogged exhaust (catalytic converter)