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Hey, just looking for some advice as to where to start diagnosing a few codes. Don't wanna just throw money at it, so hopefully you all can help avert that! 🤣
2004 se7 140,000 miles P1300 P0300 P0304 p0308
Service engine light flashes, even at cold start/idle.
I unplugged the MAF sensor, as in the past, the p1300 code has almost always been the MAF, and when I unplugged it, the engine stumbled, indicating to me that the MAF was probably atill functioning. However, when I plugged it back in, absolutely nothing happened, which I thought was a bit odd.
It appears to have the original grey spark plug wires, which I'll try and check for cracks/jumping spark, and was also thinking failing coil packs, considering it has random/multiple misfires in addition to the consistent misfires on cylinder 4 and 8. Just hoping to avoid doing that nasty job unless neccesary at this time. The weather has been quite poor, so being outside for several houra in thr snow and wind is less than appealing.
Maybe focus on clearing 4 and 8 misfires. That should take care of the random multiple code too. Spark plugs can be cheap if you stay away from the high end, so read the plugs and replace with a new set. All eight is best so you can compare all cylinders, then go from there. Also check fuel trim values and monitor O2 sensor trends in real time.
Maybe focus on clearing 4 and 8 misfires. That should take care of the random multiple code too. Spark plugs can be cheap if you stay away from the high end, so read the plugs and replace with a new set. All eight is best so you can compare all cylinders, then go from there. Also check fuel trim values and monitor O2 sensor trends in real time.
Yeah, I did a little digging this afternoon when the sun was out- it was still cold, but I hate just sitting around. I think I'm just gonna bite the bullet and revamp the entire ignition system, and replace all 4 o2 sensors in one go. Those are all original components it seems, aside from the o2 sensors. So they can be replaced, it isn't terribly expensive.
Curious to know what the gaps measure on the old plugs. Too big from wear could cause misfires. Looks like one had a broken insulator that can cause misfires. I have had good luck with NGK plugs. If all is well, plug colors should be nearly the same for all cylinders. I also noticed none of the crush washers looked like they were crushed. If the plugs are not fully seated (potentially leaking) that could also cause misfires. Sound like you are on the right track. Good to take care of the easy basic stuff first.
Hm....well.... New NGK plugs, wires, and coils. Still misfiring. CEL is flashing. Codes were for cyl 4 and 8, with a random misfire, which is why I just went straight to ignition stuff. They 100% needed to be preplaced, as I'm quite certain they were the original plugs, wires and coils @128k miles. My younger brother borrowed my code reader, so I can't see if the codes moved or anything just yet, just feeling kinda discouraged. The vehicle sat for 4 or 5 years, and had just under1/4 tank. I put fresh 91 in it, and a super strong fuel system cleaner. Checked the IACV and it looked freaking fantastic! Very little dirt or anything, and it spun freely no felt resistance. Sprayed some cleaner in there anyway lol. Throttle body is pretty gross, so I'll clean it next. The MAF is a curious thing... when I unplug it, the engine seems to get kinda unhappy, but doesn't get better when I plug it back in. Didn't, and don't see any signs of headgasket issues anywhere, and cykinders 4 and 8 are obviously not next to each other, so they can't be leaking into each other, no gross oil, no white smoke, doesn't overheat, nothing like that. Please help!
Multiple misfire?
