Hi 1997 Jetta. Did a tune up last night (plugs,wires,cap,rotor). Car ran well initially when started then the check engine light came on..Took it out for a test drive the check light was on and off intermitantly.When the light is on the car hesitates stumbles and seems to lack power, as soon as the light goes out the car pick up and runs great..... anyone have any ideas...I am at a complete loss...thanks in advance for any help
Mike
light stays on now... before was on/off

 

did you cross wires

 

Car is idiling great...so i know its not a crossed wire....
the check engine light is on and off intermitantly.... when off the car runs great
when on the car lacks power and seems to stumble a bit

 

did you have to pull any of the plug wires back off? they are really hard to remove once they are seated and you could have damaged it causing an intermittant misfire. take it to autozone and let them hook up their code reader.