Having troubles with my SC miata
 

I have a sebring supercharged miata (1.6). About two weeks ago I went over a speed bump and separated my test pipe from the rear of the exhaust a hair. It didnt effect the running of the car at the time. The day before yesterday i was driving down the road and the car just started stumbling all over itself.... I pulled over and looked at it and didnt see anything obviously wrong with it. I finished the drive home. I noticed that if i was "dead" in it, it ran fine. when i was idling or didnt have my foot all the way in it, it would yoyo and spudder and backfire.

What i have checked last night. I swapped fuel pumps with my parts cars, put in a new pcv, cleaned all the engine grounds and made sure they were firmly attached, I did a shake test on the harness and cant get it to change the running of the car, i pulled the spark plugs and they were pretty blacked up. The coil pack is 3 months old.

I had problems with the ground being loose once and they pcv went bad so those were the first things i checked. Today after i get off work i am goign to go reseal the exhaust and pull the ecu(stock) for 30 mins or so to reset it.Any suggestions? Thanks for any help given. :noob:

More details about your setup will be helpful.

Bad coil, vacuum leak, failing cas. What's your fueling control?

It seems my header was cracked between the motor and o2 sensor.