Misfire

[Mcglaughlin9]

i am a new member. i own a 2003 Pontiac Vibe zz engine. i am coming across a rough idle. 3 weeks ago check engine came on, said p0301,p0304 (cylinder 1,4 misfire) so i replaced all 4 coil packs and all 4 spark plugs. Light is still on so i cleaned throttle body and mass air flow, light is still on. im thinking possibly spark plug wires next. any suggestions? i have about 175k miles on it and i am 2nd owner. i also have more question about issues with vibe if you guys can help. thank you

[Bookworm]

Did you make sure to clear the codes after replacing the packs? If not, do so.

It can also take the car a few days to retrain itself, especially if it's cold.

[Mcglaughlin9]

Yes i reset the code but a week after i replaced packs, i got an oil change and light came back on, its still saying p0301abd p0304

[Caretaker]

What brand of plugs and ignition coils? We can't just throw anything into these Japanese engines. They revolt if Denso is not used.

[SeattleJeremy]

Did the car start showing this issue after it got cold out? If so I suspect the intake manifold gasket has failed. This gasket is a known weak failure point in the early 1ZZ Vibe/Matrix. The newer gasket is a better design.
While you are in there I suggest replacing the TB gasket.

[Mcglaughlin9]

What brand of plugs and ignition coils? We can't just throw anything into these Japanese engines. They revolt if Denso is not used.

Amazon “standard motor products” for coil packs and ngk plugs.

[Bookworm]

I'd point at a gasket as well, at least to a degree. Notice that 1 and 4 are the outside ones, which would be the most visible, as it were, to a gasket problem. The inner ones have more distance to the outside for a leak.

[Mcglaughlin9]

Im sure it would help to mention there was just alittle bit of oil on the coil packs about halfway up and it was a light ring of oil.

[vibrologist]

It looks like you are in for a do-over +.

The + is the valve cover gasket. Oil in the plug tunnels will cause misfires. I'd also spring for Denso plugs and coils and replace the intake manifold gasket and TB gasket. If you haven't thrown away the old coils you may clean them from oil traces and try them out.

[doubl3d]

@Misfire is the problem solve now? Coz we almost have the same problem that's why I follow and read this interesting thread

[zbyers]

It looks like you are in for a do-over +.

The + is the valve cover gasket. Oil in the plug tunnels will cause misfires. I'd also spring for Denso plugs and coils and replace the intake manifold gasket and TB gasket. If you haven't thrown away the old coils you may clean them from oil traces and try them out.

I second vibrologist.

[tpollauf]

Not sure if the original member here ever solved their problem BUT as of last night, my 2004 Vibe GT was running great and out of nowhere it started misfiring! Decent temperatures 45-50'f, slightly damp as it was raining earlier, did NOT drive through any deep puddles, conservative driving too. Anyways it threw the p0304 code (cylinder 4 misfire detected). After reading on here through several posts, I figured it may be the coil pack OR oil trapped in the spark plug well. I do have a pretty good oil leak coming from the valve cover (I'm pretty sure anyways) and possibly oil got into the well as a result of this? We'll see. Going to get it into my shop in the next day or two and get it fixed. Will follow up with my findings later

[tpollauf]

Will follow up with my findings later

Update. Coil pack was definitely bad. Moved it over to cylinder #3 and sure enough, got a p0303 code (cylinder misfire # 3). Got a new Denso coil pack from my friend who works at Advance auto ($59.80, not sure if that's a good price or not), changed out plugs and gave it an oil change while in the shop. Components looked to be original, 18 years old & only 171K miles. Runs like a champ again