My 03 CL 6-S is not running properly. 85k on the ticker, and well maintained, I washed the engine bay (as I frequently do) last Saturday. Driving it to work Monday, it began to misfire randomly, and the engine light was blinking.

I pulled the codes with my reader and got 1399, 1301-1306. Basically, 1399 is a general misfire code and the rest are the cylinder codes. All of these come off the crank sensor though - so they aren't completely accurate necessarily....

I pulled all the coilpacks and plugs, cleaned everything up, and fired it up after resetting the ecu. Still missing. Killed the engine. The two cylinders in the rear bank closest to the passenger side had wet plugs. I replaced the coil packs on both cylinders, still nothing.

Replaced all the spark plugs - still nothing.
I pulled the connector off the coil packs one at a time, and the only two that don't make any difference with how rough it's idling are these two.

Having replaced the coil packs and the plugs, I took apart the EGR and cleaned it with electro cleaner, and popped the primary and secondary O2 sendors and cleaned them with electro cleaner as well. ECU reset - still no difference.

I'm not sure what else to check at this point? I let a high velocity fan blow on the engine all night last night to displace any water - but this didn't matter.

Any ideas? Help appreciated. I've searched the forums already and it seems I've tried everything recommended short of replacing the computer - which just doesnt make sense.

 

make sure that all the connectors are properly plunged in. a connection might have gotten lose, or a ripped wire from its connection or other point of contact

 

I pulled each coil, one by one and left it connected, with an extra spark plug in it, and enough space to arc to something grounded on the car. All the coils are firing, and seem to be fine. All the injectors also seem to be pulsing. If I were to guess, I think the cam skipped a tooth while accelerating and it's out of time now. Investigating further....

 

When I had this problem check your ground wires, for sum reason that I'd seen on like three others CL-S some of the 01 have two ground on from engine to chasis then one from the trans mission to the engine... Now what was happening with mine was that we would take it for a test drive, she would be fine then just sitting in park running all of a sudden missfires on all cylinders when scaned, that was pissed off day let me tell you that, then it clear up on it own ... So check that also u never know !!! also make sure your ground wires aren't Frayed ...

 

I had p0300 , p0399, p0302, p0304, and p0305. My car was shaking like a mofo , and would no go over 60MPH. I bought 4 coil packs off ebay for $75 shipped and replaced coil 4 and car is back to 100%!

 

Also look inside your coil packs there is a metal spring Like in pens in them.
Make sure that spring looks silver and good, my coil pack that was bad the spring was blackend and melted!

 

Cylinder #1 is only holding 25psi - it's dead. Time for a new engine....