i just put my stock ecu back in to attempt to smog and i get down to the place and pass all the emissions tests, and visuals and right at the end of the test i get a cel that when i get home says 71,72,73,74. miss fire on all cylinders.. its NOT bogging.. not feeling wierd at all. and doesn't throw this code on my chipped p28. i know its not miss fireing but i don't know why it would be throwing the codes. motor feels and sounds fine.

 

did u try to check the ecu? is it messed up.

 

you put your stock ECU back in...hmmm.... what mods do you have that requires a modded ECU? maybe something is screwing with it?

 

well the stock parts i put back on are the stock intake, a carb legal dc header, the stock cat. the mods i still have are my skunk2 stage 1's, head work, vafc is still in there, i just don't get it. i mean. i certainly wouldn't have passed the emissions part of smog had i actually been miss firing. anyway to disable the sensor in the dist. for the test so i can get registered?

 

Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensor which is attached to the crankshaft. If misfiring strong enough to damage the catalyst is detected the MIL will blink druing the time of its occurrence, and the trouble code will be stored. Then, after the misfire has ceased, the MIL will come on.

If misfiring that increasses emissions is detected druing two consecutive driving cycles the MIL will come on and more codes will be sotred.

Possible causes:

Fuel injector clogging , fule leakage, air leakage
Fuel injector circut open or shorted
spark plug carbon deposits, fouling, malfunction
Ignitino wires open, leaking
Distributor malfunction
Compression low
Valve claearance out of spec
VTEC system malfunction
HO2S
Ho2S circut

Check the fuel injectors function:
start the engine and listen for a clicking sound.

Do you get any other Codes than misfire?

 

problem solved. i had it leaned out to much at idle for the stock ecu. i had left the vafc idle settings for my chipped p28.