BigGary

hey all, i was driving home from work today, had a little fun may have gone past the redline for a split second then my car started running rough, read the DTC's and i got p0301 and p0304 (misfire detected cylinders 1-10) i'm pretty new to the CoP concept so anyone know where i can start to try and solve this issue?

everett

Unless you increased your rev limit the factory setting won't allow you to do any damage. My best guess is a vacuum leak. P301 is misfire in the number one cylinder and p304 is misfire in cylinder 4. How old is the gas and could it be fuel impurities. For sets the rev limit low enough that even if you bounce the rpm of the limited it shouldn't do any damage. And it's rare that a coil goes. How many miles on car

cliffyk

+1 as to "how many miles on the car", also how many on the plugs--also check the COP boots and make sure they are not cracked, hardened, or burnt smelling...

Reset the codes and see if they come up again...

BigGary

155,000KM on the car, plugs dunno just bought it still getting into the freshening up... i cleared the code last night, got in the car this morning and it runs good again... sooo im confused but worried, i have a 700km trip on sunday and im gettin nervous... oh and the gas is new... but from a gas station that i usually dont use, supposed to be the "shell cleans ur sh*t up" 91 octane, pff doubt it

cliffyk

155 km = 5 km less than the recommended service interval (160 km)--so it may be they have never been changed. Do that first and while the COPs are off make sure you inspect the boots as described above...

The misfire monitor works by measuring the crankshaft velocity and acceleration of each firing event (read more here). If the plugs are nearing their end they could very well have misfired at the high engine speed enough times to trigger the DTC.