Yes, a bad cat can cause jerking like that. I've had more than one cat that was broken up inside. When the insides break apart, they can start to turn every which way which causes a huge exhaust restriction. The engine will be fighting to breathe...take a big deep breath yourself, then hold your hands over your mouth and nose as you exhale and see how you like it! The restricted exhaust flow could also be pushing back through the EGR valve, which also will affect how the engine runs.

 

Nice explanation

 

Well, in a way, an engine is a lot like us. It breathes in air, it eats (fuel), and it gets rid of unwanted byproducts through the tail pipe.

 

 

umm


ahhh

oh, never mind



did i miss anywhere that he scanned for codes to see if there are any?

 

My question as well, is the engine light on? Depending on the kind of jerking it could be a bad ignition coil. Had to replace one on my 3.8 once.

 

No codes, no lights