My wife and I just purchased a 2008 Wrangler. We bought it with a cat converter code so we we had the two factory converters replaced and the other deleted. It had the bad smell and miss when accelerating while driving. After that, we got O2 Sensor codes for all the sensors. Upon inspection, I found Bank 2, Sensor 1 unplugged from the exhaust shop. I plugged it back up and only got codes for both upstreams and P0303 for Cylinder 3 misfire. I replaced the upstream O2 Sensors and still had the P0303 so then I replaced all of the spark plugs. The code reset until about 5 miles in I still had the miss when accelerating and the CEL start intermittently flashing. The miss is A LOT better and the light comes and goes but the miss is always there and the code is P0303, P0300, and P0430 now. Other than the miss while accelerating and tough idle, it’s much better to drive.

The guy I bought it from had the #6 Injector replaced along with the ignition coil, plug wires, and spark plugs within the last year but granted this was done before fixing the cats. One of them was completely clogged and the other one almost was.

Can someone give me an idea of where to go and what to do next? I plan to replace the coil and wires again today and maybe the PCV Valve.

I’m somewhat mechanically inclined but I don’t want to start hanging parts on it without a fix.

 

Welcome Alabama.. Good group here on JKF.. You should check for loose connections and possibly a wire rubbed thru.. several months ago I recall a post (on 1 of the 2 forums I read) where the culprit for 1 of your codes was a wire that had either rubbed or was loose corroded. Check all the wiring to the injectors, coils, etc ..

 

Thanks Jay! I’ll do that! I just replaced the ignition coil, PVC valve, and plug wires also! I’ll be test driving later this evening! I’ll check all the wiring tomorrow to see if there’s anything off! It’s more of a shudder than a miss when accelerating but the code that keeps coming back is P0303 for cylinder 3. I’ll double the the wiring to the injectors later or tomorrow! Thanks again for your response!

 

Keep the forum updated,, your findings and resolution will assist in the future.

 

Will do! Thanks again for your help!

 

Our jeep is running good now after also replaced the coil pack, spark plug wires, and PCV valve! No CEL flashing or coming on at the moment. I’ll post if something changes anytime soon!