LOUDandPROUD96

When i bought my car it had a misfire, (p300 code, random multiple cylinder misfire) so i replaced the original cap and rotor with a msd unit. after this didnt work i decided to change my plugs and wires when i did my headers. the scanner says it still has a p300 now. Anybody have any suggestions or have similar problems?

PunishedU

iTrader: (1)

When I had mine p0300 code, I replaced plugs, wires, coil, and 02 sensor which i knew was bad and that took care of it.

LOUDandPROUD96

thanks man, i do have a bad o2 sensor so ill try replacing that first, hopefully it will get the job done. if not i guess ill go for a new coil. thanks again.

PunishedU

iTrader: (1)

I have heard from a few people that replacing the 02 fixed the problem for them also. Definately do that first.

the_merv

iTrader: (88)

Make sure you don't have a wire touching a Header..mine did that and misfired.

sdm1234

iTrader: (8)

a faulty EGR pump will also throw a random cylinder misfire code, as well. that happened to me.

LOUDandPROUD96

thanks for all the help im throwin the o2 sensors in today and ill update if it fixes the problem

WhyHelloOfficer

iTrader: (5)

If it isn't the coil itself, you can take a look at the ICM -- that can be the culprit.

More than likely the O2s are what is causing your misfire. I also second double checking your wires -- its common to think the wires are run correctly but they have found their way back in contact with the header primaries.

the_merv

iTrader: (88)

O2's might be a problem with mis-fires? Mine does it at 5500 and up when it gets really warmed up. I don't have EGR, so I know it's not that.

LOUDandPROUD96

well i installed all the o2 sensors and now its saying i have a cylinder 5 misfire. if your standing in front of the car facing it, cylinder 5 is the third on on the right correct?

sdm1234

iTrader: (8)

yes, correct.