Lots of problems

[johnnyonthespot]

I have a 2000 wrangler with a 4.0 liter engine and a 5-spd transmission. It is throwing codes for misfires or cylinders 3&4, and random misfire and is running really rough. It has the icons for o2 sensor, o2 heater sensor and catalyst and the check engine light flashes above 2500 rpm but stops when the rpms are returned below that. I have replaced the coil pack with no changes and inspected, cleaned and re-gapped the plugs. They didn't show any signs of fowling. I have also replaced the o2 sensors which helped for about 30 miles and I've run cataclean through it. I also checked the fuel rail pressure and it read 30 psi with the ignition on but engine not running and 47 psi with the engine running. I'm back to square 1 now except my pocket is a few hundred dollars lighter . Would you suspect that the catalytic converter is plugged?

 

[glowell222]

Best approach is to uncork it and see if you are getting the same symptoms. It will be loud.

 

[johnnyonthespot]

By uncork it, do you mean take the guts out, pipe around it, or just go straight pipe.

 

[johnnyonthespot]

Best approach is to uncork it and see if you are getting the same symptoms. It will be loud.

By uncork it, do you mean take the guts out, pipe around it, or just go straight pipe.

 

[glowell222]

I would go straight pipe, temporarily. You will get the O2 sensor lights, but you will then be able to see if your cat is the issue.

 

[primetime4]

I had a similar issue going above 3100 rpms. Had the dealer and no less than 2 shops try to diagnose and basically got a run around. One shop did test the cats for flow and did not think that was the cause.

Ultimately finding and installing a Mopar crank position sensor resolved the issue. Replacing this was when the issue started in the first place but the challenge is finding a Mopar unit was almost impossible.

I also asked the dealer and shops about the "relearn" procedure and no one had a clue. I think if you can find a place with the right unit to perform that procedure would be a good place to start. Otherwise, Mopar crank sensor is what I would be on the lookout for.

https://wranglertjforum.com/threads/dealer-suspects-a-cracked-head-what-do-the-experts-think.62051/

 

[johnnyonthespot]

I would go straight pipe, temporarily. You will get the O2 sensor lights, but you will then be able to see if your cat is the issue.

Thank you

 

[johnnyonthespot]

I had a similar issue going above 3100 rpms. Had the dealer and no less than 2 shops try to diagnose and basically got a run around. One shop did test the cats for flow and did not think that was the cause.

Ultimately finding and installing a Mopar crank position sensor resolved the issue. Replacing this was when the issue started in the first place but the challenge is finding a Mopar unit was almost impossible.

I also asked the dealer and shops about the "relearn" procedure and no one had a clue. I think if you can find a place with the right unit to perform that procedure would be a good place to start. Otherwise, Mopar crank sensor is what I would be on the lookout for.

https://wranglertjforum.com/threads/dealer-suspects-a-cracked-head-what-do-the-experts-think.62051/

Thank you

 

[Larry L TJ]

Thank you

Is this the replacement number for the Mopar 56041819AA? https://www.rockauto.com/en/parts/mopar,56027865AB,crankshaft+position+sensor,7196

 

[Link]

I have quite a few miles on an Echlin crank sensor with zero issues. Napa part

 

[Moglocker]

I have a 2000 wrangler with a 4.0 liter engine and a 5-spd transmission. It is throwing codes for misfires or cylinders 3&4, and random misfire and is running really rough. It has the icons for o2 sensor, o2 heater sensor and catalyst and the check engine light flashes above 2500 rpm but stops when the rpms are returned below that. I have replaced the coil pack with no changes and inspected, cleaned and re-gapped the plugs. They didn't show any signs of fowling. I have also replaced the o2 sensors which helped for about 30 miles and I've run cataclean through it. I also checked the fuel rail pressure and it read 30 psi with the ignition on but engine not running and 47 psi with the engine running. I'm back to square 1 now except my pocket is a few hundred dollars lighter . Would you suspect that the catalytic converter is plugged?

I would just remove the o2 sensors and stick a camera down there,you can see if they are clogged

 

[glowell222]

I have a 2000 wrangler with a 4.0 liter engine and a 5-spd transmission. It is throwing codes for misfires or cylinders 3&4, and random misfire and is running really rough. It has the icons for o2 sensor, o2 heater sensor and catalyst and the check engine light flashes above 2500 rpm but stops when the rpms are returned below that. I have replaced the coil pack with no changes and inspected, cleaned and re-gapped the plugs. They didn't show any signs of fowling. I have also replaced the o2 sensors which helped for about 30 miles and I've run cataclean through it. I also checked the fuel rail pressure and it read 30 psi with the ignition on but engine not running and 47 psi with the engine running. I'm back to square 1 now except my pocket is a few hundred dollars lighter . Would you suspect that the catalytic converter is plugged?

How did it go? All good now?