Bad engine stutter at low RPMs. help

[twominuteturn]

I'm in need of some help here.

As of two days ago, my 04 linear (145k miles) has been shuddering and shaking at idle and low rpm. When ascending a hill the rpm drops, shudders hard, downshifts and revs, then CEL flashes briefly and things level out. At cruising speed though, she's as smooth as glass. It's only when I slow down or stop.

I've done a lot of research, and there are a lot of ways this could go. So here's what I know: code P0301 shows up. Misfire in cylinder one. Changed the plugs, still 0301. Also, I have a P0442 and P0455 - evap leaks. Are these in any way related? I ran through some injector cleaner in case it happened to be a bad injector, but haven't seen any change. I also moved a coil around to see if 0301 changed to any other 030x, but no avail. So I don't think it's a coil... (unless I didn't give the OBDII enough time to rescan..)

Could it be transmission related? Shifting is obviously running rough, and I haven't ever had fluid changed in the 1.5 years I've owned it.

I'm a DIY kind of guy, so I'm reluctant to hand it over to a mechanic and trust he doesn't give it a low-grade fix. Any hints or knowledge on this would be excellent!!

[greenydsm]

Originally Posted by twominuteturn

I'm in need of some help here.

As of two days ago, my 04 linear (145k miles) has been shuddering and shaking at idle and low rpm. When ascending a hill the rpm drops, shudders hard, downshifts and revs, then CEL flashes briefly and things level out. At cruising speed though, she's as smooth as glass. It's only when I slow down or stop.

I've done a lot of research, and there are a lot of ways this could go. So here's what I know: code P0301 shows up. Misfire in cylinder one. Changed the plugs, still 0301. Also, I have a P0442 and P0455 - evap leaks. Are these in any way related? I ran through some injector cleaner in case it happened to be a bad injector, but haven't seen any change. I also moved a coil around to see if 0301 changed to any other 030x, but no avail. So I don't think it's a coil... (unless I didn't give the OBDII enough time to rescan..)

Could it be transmission related? Shifting is obviously running rough, and I haven't ever had fluid changed in the 1.5 years I've owned it.

I'm a DIY kind of guy, so I'm reluctant to hand it over to a mechanic and trust he doesn't give it a low-grade fix. Any hints or knowledge on this would be excellent!!

I would suggest getting a new coilpack. These cars are very famous for misfires due to them

[twominuteturn]

ALTHOUGH, which one is cylinder 1? I moved the coil on the far left and far right, so I might have missed it if it's one of the 2 in the middle. Does anyone know the numbering of the cylinder firing order?

[Diggs]

Fires left to right. Could be the wires to coil one....

[twominuteturn]

Originally Posted by Diggs

Fires left to right. Could be the wires to coil one....

how would I check that?

[sleeper900]

Originally Posted by Diggs

Fires left to right. Could be the wires to coil one....

THIS.

I had to buy a harness to replace mine...the connector was fried and wouldn't make contact properly every so often basically making it act as though the coil pack was junk.

[SaabMick]

You do have a lot of miles if those are stock coils, but the wire thing sounds plausible. Have you checked the gap on the new plugs? And if the code wasn't cleared, it might still be showing you the old one...not sure though what the circumstances were between readings

[Tony93]

I used to have an issue where it almost dies at idle but at speed, no problem. It was a vacuum leak.