Ive been chasing a random misfire for about a month now. Doesn't always do it, could be cold or warm, will have a misfire during idle and won't pull till about 4k then its ok. No codes for the first while. Ive changed the MAF, TB, crank and cam sensors. Check / cleaned all the grounds. all the spark plugs seem good replaced a couple k ago with oem. Car has z-tube, k&n and invidia gemini.

started giving codes, Borrowed an old snapon scanner and P0132 P0152 P0138 P0158 all high voltage o2 sensor. monitoring the voltages they are well above 1v when its running bad and all normal fluctuating from .1 to .8v when its running good.




they fluctuate but are over 1v. can't see it being all 4 sensors bad.. if i unplug both downstream it seems to run well but still has a telltale randomly occurring small misfire, will great for hours sometimes days and then it comes back. Im not sure if the high voltage is due to the misfire or the cause of it. maybe I have more than one issue? I have one coil pack spare that i have been slowly replacing each one with to see if it resolves but no luck yet. never gotten misfire code.


Any help would be appreciated!