For anyone who has the time..

[Mopud]

Yes, all previous codes are gone, just the flash is left.

I only have one CAT, 1x upstream and 1x downstream oxygen sensor.

[Mopud]

After 400km+ of driving and a whole load of offroading, i was casually driving home late last night on the highway when the engine light came on and stayed on. Error codes report:

P300 - Multiple Cylinder Misfire
P302 - Cylinder 2 Misfire
P303 - Cylinder 3 Misfire

At least it has given me something to focus on! Hopefully it is also the cause of the flashing CEL.

[wjtom]

the flashing cel light on any obd2 car is for a misfire,warning you of converter damage. i went through the exact same thing with mine and the cps was bad.mine was a dorman replacement where you get the whole drive assembly.the whole unit from chrysler is 300 dollars from napa its like 60 dollars.not only was the sensor just bad but the cresent shaped trigger wasnt correct either.is your drive an oem drive?how about the sensor?i would REALLY look at both these pieces.are you setting up the cps with a scanner?it HAS to be done with a scan tool.you might get lucky without one but it only plus or minus 2 form 0.with 0 being perfect.it will run without setting it up properly but exactly what you are describing will happen.for some reason it may not set any codes right away either.

[SilverXJ]

Thats not your CPS. The CPS is in the bell housing and runs off the flex plate/fly wheel. CPS=Crank position sensor. The one where the distributor use to be is the camshaft position sensor, CMP. I purchased one from the dealer years ago(with the drive) and at the time it was like $100. I tried to purchase one from NAPA,thinking theirs would be a good aftermarket unit. However it was crap. The trigger wheel wasn't attached correctly and I couldn't even get a tooth pick through the holes to line it up.

[wjtom]

same here mine came from napa.which is just a dorman one rebranded.

[Mopud]

You raise a good point about checking the crescent piece on the top where the cam sensor plugs in, i might give it a closer inspection. I picked up an airtex wells replacement cam sensor from rockauto back in dec which was the one i installed. the drive however is still oem original from new.

thanks for the replies

[Mopud]

Just to put some closure on this one for the sake of completion, i had the Jeep off the road for 3-4 months while i sourced a new thermo fan controller. when i finally got it running again i did a little research into the error i was having - the engine misfire and flashing CEL at highway speed - turns out my cam gear was out of whack. the old toothpick alignment job seems to have fixed these problems right up.

so overall the problems were:

loose oil pump drive assembly, faulty cam sensor and then loss of cam sensor alignment. the busted catalytic converter didn't help as well with them not supplying one that is Californian emissions compliant. the pinging sounds i was complaining about when giving it a little bit of stick have for the most part subsided now that the timing is in check. engine temps are also well and truly under control. life's good.

[Cheromaniac]

Glad to hear you got it sorted out mate.

[superstingray77]

Mine did the flashing CEL when the cam was toast, cylinder 3 misfire and pinging under load since there was not sufficient lift to exhaust the spent gasses. I realized the cam was failing when we were 300 miles from home. Added a TON of octane booster to the tank of 93, flushed the engine, changed the oil and drove it 300 miles home. Still pulled strong on freeway but anything over 1/3 throttle or keeping speeds on hills would cause the CEL to start flashing so I would just back off. Increased cyl pressure blows the spark out. Maybe try gapping plugs tighter? Also put a dial indicator on the valves and check the cam for wear. Mine was still running/idling fine and when I pulled the valve cover everything seemed normal. I just had a strong gut feeling what it was, that and the metallic black nail polish i had for oil

Glad you got it sorted, somehow I missed reading the last few threads

[Mopud]

Not going to lie, I held it at speed on the freeway today and the cel came back. I'm going to hook a computer up to it because I noticed that when the cel was blinking the scangauge was reporting that it had switched to open loop. When the flashing stopped, it went back to closed loop. Something to focus on there, has to be another sensor going south and I am sure abnormal readings will make that easy to diagnose!