New Poster here. Thanks for your insights!

having a misfire issue, hoping for some like-minded advice.
For about a year, the jeep would periodically ‘lurch’ while accelerating at low rpms. From the reading I gathered, it was a crank position sensor issue. Easy replacement so I did about a week ago.

the other day it was -30 so I fired the jeep up to warm it up. Check engine light came on.

I’ve been driving for a couple days since (been really cold here!) and the cel remains on with a misfire and cps code. It idles really rough at startup and the odd time the cel flashes 8 times.

I have it booked in but not for a week at my mechanic. It’s a 2012 but I only have about 40k on it. I’ve had no other issues only had to change a t-stat.

I’m hoping it’s not the dreaded cylinder head issue.
Anyone have a similar problem?

since I changed the cps, and the cold weather it’s been not running right. I’ve decided to park it until i get it into the shop in a week.
I appreciate your thoughts here very much!

 

The only thing that I can fathom is that you typically do a cam/crank relearn when changing one of those sensors. In a normal situation it not 100% required cuz the jeep will figure out syncing things up in a few cycles, but maybe the extreme cold temps not allowing the engine to get up to temp in a reasonable time are throwing a wrench in that process. That extreme cold is the one thing that really stands out at the moment. If it were mine I would have put the old sensor back in to see if it reverted back to how it was.....running ok but lurching. Did you use a brand new factory sensor from the dealer? These days, with all the counterfeit parts, can't even trust "factory" things off ebay unless you are certain the seller is a dealer. Sensors like that are definitely something to stick with factory.

 

Thanks Jedi.
I that’s a good thought putting the old one back in, I think it’s still in the garage ina box. I’ve heard some factory sensors just don’t jive unless it’s from the dealership.
i bought it from the local auto parts store but it’s for sure different than the one I took out…

I’ll try that tonight.

Any thoughts on what the lurching could be? It’s the reason I put the new sensor in anyhow.

 

Problem solved.

reinstalled the old sensor and all is good again.

don’t buy “cheap” aftermarket sensors. Go to the dealership!