Hey Scott, I have a 2005 Nissan Altima 2.5L with 125k miles on it. It's been burning oil like hell. It also smokes badly. There is a code for P0420 "catalyst efficiency low" but other than there's nothing wrong with it. I took it to a mechanic and he said something about oil pressure sensor, does that have anything to do with it.
Piston rings went causing excessive blow by and destroyed the cat. Would’ve needed an engine and a cat to repair so good thing you got rid of it
- P0420 is a catalytic converter code. If your vehicle is burning a lot of oil, it's also destroying the cat.
Yea thats what I thought too, Im betting the cat is good but clogged from all the oil. Maybe the smoke is from the burning of the oil on the cat? I know they get super hot
The cat is designed to burn gases, not liquid. Oil destroys cats. Period. Investigate, read.
Makes sense. I got rid of the car anyways, I just never seemed to find out the issue.
Those older 2.5 L engines were known for oil consumption, bad cats, and blowing head gaskets, you said that it has a code for bad catalyst efficiency low, could be the cats going bad. I would also check if you have any blown head gasket.
