Mystery problem with 99 Pathfinder

[99PathFinder]

Hello everyone, I've been having a problem with my Pathfinder that my mechanic or I can not figure out.

It's a 99 5spd with 220,000km on it. aaaannndd here's the issue.

About a week and a half ago I had driven my truck about 60km, got gas and went to the gym. When I got back about 90 minutes later it started up fine but as soon as I pulled out of the parking lot it was sputtering and really jerky. As soon as I put the clutch in it would go back to idling perfectly fine. It would rev up to about 3,000 rpm but no further. As you shifted up the jerking got worse and worse.

I made it home doing about 10km/h but it was a saturday afternoon so nothing was open until monday. Monday morning i took the truck in...ran completely fine. The mechanic ran the diagnostic even though I had no engine light on (does not work and is a whole other electrical issue). He ended up clearing an 02 sensor and ignition sensor issue and replacing the distributor assembly.

Ran okay for about a week. Felt like there was less power and it got a little sputtery (sorry for lack of better term) at certain times accelerating.

Then monday morning I was doing about 80km/h on my way to work after running around and doing errands and the same issue started again. Real jerky and would not accelerate well. When I pulled over and popped the hood. Smoke was coming from the passenger side exhaust manifold area and it smelt of burning oil.

Mechanic could not find any major leaking oil or why it would be burning. He replaced the O2 and ignition sensor but after letting the truck sit for half a day it was running fine again.

I drive about an hour round trip to work each day and really rely on my vehicle. I made it to and from work today but I can still feel the sputtering at times.

THANK YOU for whoever read that long explanation of what is happening and if anyone could give me ANY idea what's going on it would be very much appreciated.

Cheers,

Scott

[smj999smj]

Without evidence of something burning on the exhaust, there's a chance there could be a restricted catalytic converter on that bank. I would have an exhaust backpressure test performed on that engine bank.