Ok so i get a PO300 random misfire, on my moms 99 max i have checked coil packs all work great, injectors all spray, and has new plugs in it... ANY CLUES ON WHAT ELSE IT COULD BE? also it has a new MAF in it.. Any help would be appreciated.. Thanks in advance

 

t could be the knock sensor, it controls your timing, im not 100% sure it could cause a misfire but its possible, when the plugs were put in were they gapped properly?

 

Might have an intake leak some where - maybe the intake manifold.

 

KS wont cause misfire, only loss of power and low MPG. Why was the MAF replaced and did the misfire start after or before MAF swap? How did you check the coils? Working at idle doesn't mean they will work under load, cylinder pressure increases resistance at the plug gap.

 

before i changed out my ks i had a misfire under load, as soon as i changed it the stuttering and misfire went away

 

KS was replaced when i did the VCG and Intake gaskets,,, MAF was swaped because it didnt work anymore would let the car go above 1500 rpm at idle, the misfire was there before the swap of the MAF and the new plugs i put in it. I checked coils by unpluggin them but not underload,

Now the wierd thing is that it doesnt do it all the time, and when it does it you can barely feel it but its there