Help with a diagnosis (possible heat soak / bad cats?)

[NCLJ]

Picked up a MAP sensor and will see if I can get readings this evening.

 

[NCLJ]

New sensor and no reading. There is voltage to the plug.

 

[NCLJ]

Started this and got this

 

[JKP]

Check the wiring. After that, maybe PCM?

You can check the troubleshooting procedures in the FSM under Powertrain. PDF is available under Resources section on the forum.

 

[NCLJ]

Changed the sensor back to the old one, cleared code and was ok. I put the new one back in and no code. Maybe the plug wasn't seated all the way.

Changed the fan clutch last night and it runs perfect. Took it down the highway at 70-75 and never seen above 212 on the OBD tool. I will have my son drive it today when it gets hot out, will report back if.

 

[Jay MacLeay]

2006 LJ 6 speed manual.
My son took ownership of the Jeep last week as he just got his license. Him and a few buddies went out cruising. He called me after they had stopped at a gas station and said there was a check engine light. He was able to limp home. Read the code, it was Cyl 3 misfire. Cleared the code and drove it down the road, it felt fine.

2 days later, it does it again, this time, it is saying multiple cyl misfires detected. Clear the code, wiggle some things, take it for a drive, come home let it sit. Fire it back up and you could instantly feel it bucking but never threw a code.

I noticed that the temp gauge is sitting at 210, this jeep has never sat at 210, always a little less.

I changed the crank sensor and thermostat and burped the coolant system. Also added about half a can of seafoam.

He took it down the road, pulled in the garage, still running 210. I let it run in the garage while we look over things. I go to the back of the Jeep and instantly smell rotten eggs. I know this is a sign of bat cats, but could it have been from the seafoam?

The Jeep is a well known Jeep repair shop. I'm tired of guessing. They called me this morning and said they couldn't duplicate it. I told them to wait until later this afternoon when it is hot outside.

Thoughts/ideas?

Sounds like heat soak. I had the same issue happen to me on my 2005. I installed this and haven't had the issue since. https://www.quadratec.com/products/17604_1031.htm