Ok this just happened when i started it up one day. So just on that alone i figured some sensor went bad, but i dont really know what one. I checked all my plugs and wires none are cut and the plugs are a little black. So when i drive it does not have the power it used to and at 1500 - 2000 rpms the motor starts to shake bad, but past 2000 rpm it seems to run fine. The tailpipes also have alot of black carbon built up on it. Thanks for the help.

 

Typical causes would include faulty O2 sensor(s), exhaust leaks before the O2 sensors, and misfires.

 

would it be more likely the o2 sensors since it happened just when i started it up one time and nothing happened before that startup like anything to cause an exhaust leak. Plus i really can hear any leak when its running from under the car. would an o2 sensor go bad all at once and would it go bad without putting the service engine light on because mine has no light on.

 

i also think i might be missfiring because it is running so rich around 1500 rpms

 

Bad o2's should trigger the SES light, and throw a code. How old are the plugs/wires in the car? Might be time for a little tune-up.

 

the plugs are have about 15000 miles on them i replaced them when i did the headers and put autolite platinums back in with new wires. plus i looke the wires over closly and i did not find any sign damage. And if it where the plugs/wires wouldnt it affect it over all rpms? My problem only shows itself around 1500-2000 rpms and it happened just when i started it up and it ran fine the three hours before when it was parked.