Recent problem with the random misfire code (P0300) and the car going into the dreaded limp home mode. Looking around the various forums, it appears this problem is anything from the computer to dirty windshields. Clearing the code would make everything run normal for anywhere from 30 seconds to 10 minutes. I changed the plugs and wires after work since I happened to have them on hand and it was an easy "fix". Seemed to work for 30 minutes but then it happened again. This time I got a new code, the P2304 ignition coil B primary circuit high and no P0300 code. So tonight after letting the car cool down, I tried to clear the codes and even though it didn't show the fault code stored, it wouldn't come out of limp home mode. It did show the P2304 as a pending code. While idling very roughly I decided to pull the plug wires off the coil one at a time. When I pulled 1 and 4, the car really stumbled and actually stalled one of the times and there was evidence of arcing. When I pulled 2 and 3, there was no arcing and no change in the idle whatsoever. I'm hoping this indicates an actual coil problem. Picking one up in the morning and hoping for the best. Any other thoughts on this? Thanks in advance for any help.

 

Going to move you to the Stock Problems/Issues area. Check the coil terminals for rust, as there are several threads here on #3 issues.

 

Thanks. I did look at the terminals when I did the plugs and wires,I didn't see any rust.

 

So I swapped the coil out for a new one this morning. Same problem and clearing the code has no short term effect like it did before. I can pull the 2-3 plug wires off the car while it's running with no change in how the car idles and no spark; when I pull either of the 1-4 off the car will stumble and stall and there's plenty of spark coming out there. So am I looking at a control module now or are there any modules, relays, etc... between the ecm and the coil? I looked over the wires to the ignition and I don't see any issues there, although I can only see up to where it disappears in the main harness. Any help would be appreciated. Thanks

 

Do a quick dollar bill test.

 

Thanks, I'll give it a shot. Had a new syptom. So after going in and taking a shower for work, I decided to try starting it up for giggles.....it ran normal, no codes. While I don't believe in magical fixes, I figured I'd drive it work and see what happens. 5 minutes in it went into limp home mode and while it didn't show a fault logged, it showed three codes as pending P0300, P0302 and P0304. No P2304 this time. Since the codes were only pending and not logged, couldn't clear them. The saga continues.

 

Those are some misfire codes that are usually valves. Dollar bill test and some compression tests.

But not doing it all the time is odd.

 

OK, back at this again. Had to go out of town for work, etc... and haven't messed around with it. I did the infamous dollar bill test and it "failed". I'm not sure I fully buy this, but will work on doing a compression test this weekend. The reason I question it is, that it feels like it's running on 3 cylinders, which is bolstered by the fact that when I take the #2 or #3 wire off the coil, there isn't any spark and the idle doesn't change at all. So I don't know if this really rough idle is contributing to the "uneven exhaust". I am back to P0300 and P2304 codes. A mechanical problem, like valves, seems like it wouldn't run fine for a few minutes and then suddenly show up and result in there being no spark at the coil. We'll see how the compression test goes and go from there unless someone has any other ideas. Thanks in advance.

 

Fixed! Fingers crossed anyways. One of the other threads I read with similar problems mentioned that the wires that feed the coil had the covering rubbed off beneath the wire-tie that holds the locating clip. Popped the wire-ties off and sure enough, one of them had the wire covering rubbed off. Got it fixed and car started right up, no codes, no limp home mode. Took it for a test drive, ran great. Will update if something changes.