I bought an '02 Tl Type S a couple months ago and all of a sudden it started to run very rough. It shakes violently when I give steady throttle but if I let off or give it more it goes away. I got the codes read and here they are: p0300 (Random Misfire) p0301 (Misfire in Cylinder #1) p0302 (Misfire in Cylinder #2) p0303 (Misfire in Cylinder #3) p0304 (Misfire in Cylinder #4) p0305 (Misfire in Cylinder #5) p0306 (Misfire in Cylinder #6) p1399 (Random Misfire) p1457 (Emission control system leak. probably unrelated). I am only 17 so I am on a very tight budget so I can't afford to just start replacing random things on my car to see if they fix it. From what I have read I think the p1339 code is what is causing all of the misfires and receipt from Autozone says that it could be from a Blocked EGR passage or the Valve Clearance being out of range. My car was running perfectly before without any singular misfires so I am guessing there is nothing wrong with the spark plugs. The check engine light isn't on. The only lights that are on are the VSA SRS Brake and The Caution Triangle [Brake and Caution Triangle most likely other problems (._. ) ] The car is at 125,000 miles and it was running perfectly when I bought it. Does anyone have any idea what the problem is here?

 

Right, it's prob not the plugs although they are due for replacement.
More likely it's one or more of the ignition coils, so change all 6. (This happened to my CL-S.)

 

Ok I have an update. The car now has misfires really randomly. Sometimes when I start it runs smooth and the other times it doesn't. Also it can run smooth at start and then randomly it starts to rumble again. Is this a loose connection or something worse?

 

When it misfires, try pulling one ignition coil connector at a time to check that coil. If pulling one connector makes it worse, then that one coil was good, and try the next one.