It feels like riding in a bullbozer when the gas is depressed but smooth when coasting. I had a cylinder 2 misfire & battery temp sensor code. Changed the sensor & no codes since. Could this be vacuum & if so, how do I check that?

 

What do you mean by "riding in a bulldozer"? Slow acceleration? People in front of you scatter? I'm not sure what you mean....

 

As in it bounces up & down rapidly, more so in 3rd.

 

Up and down, but only under power? Any noise when it jumps? Does the bouncing change with speed? Bad joint in the driveshaft making it hop?

 

Yeah, it does sound like a driveline issue. Any difference in 2wd vs 4wd?

 

No noticeable difference with speed & it's a 2wd

 

Also, it's 4th that instantly makes it worse, not 3rd.

 

Today I got the check engine light...all 6 cylinders misfire

 

Today the rough engine under load has stopped...completely. Not even a change when going into 4th, which was the worst time. I changed one & only one part. Didn't even take anything off to inspect it. That one part?...serpentine belt. Now the only issues I'm having are a fuel smell & a bogginess when I idle too long.

 

Well the rough in 4th came back, but only from 45-55, or uphill, then it smoothes out.