Bucks hard taking off

I have researched and have not found my exact problem.

Here it is. 06 Rubi 6 speed 94k. It just started this.

Taking off, only rarely, it stumbles hard one time as soon as i start moving. I call it a hard buck. I have had a CEL for months, and after it bucks the one time, the CEL disappears. It eventually comes back. I checked the codes, and the CEL I have always had most likely has to do with me gutting the cats. It has run perfect for a year since gutting them, so not concerned with that. It only stumbles one time hard for a fraction of a second, then runs perfect. It did it a couple times in a row 2 days ago, and today on my way home. Jeep is stock. Concerned about ECM. Anybody had exactly this happen? It runs perfect the rest of the time.

Wranglerfix said:

Good morning gentlemen,

The common failures of a manual pcm are bad o2 sensors, low rpms and completely dying while driving. Have you had either of these symptoms?

I haven’t heard of a buck in a manual but I will ask my technician and will get back to you.

The summer heat and the location of the pcm causes a lot of issues. Some customers tell me that they can tap on their pcm and the Jeep will die.

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I've been driving on hotter days than when it happened and everything was good. It is just a fraction of a second and picks right back up. It only does it when taking off. It's always been able to idle off like you would when driving a diesel big rig. I don't think rpms are the issue. It doesn't die while going down the road. When it "bucks" it seems the jeep is dying for just that fraction of a second. Hope that answers it. Thanks for the help

AndyG said:

That is exactly what it's doing ...dying... a PCM is probably going to be the answer.

we all are always hesitant because we know we want a sure diagnosis before we spend the money.

People over rate the cost of the PCM replacement... Think of it as a set of tires you only have to buy one time.

the reason I say that is people just cringe about buying a PCM ..but they will brag take pictures shop and get excited and show off a new set of tires that are only going to last so long and start going downhill the second you pull off the rack.

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I'm leaning that way, just hope not. It doesn't even have 100k on it yet