Hello got a 2000 durango with a 4.7 in it i threw a check engine light 2 weeks ago saying system too lean , and bank 1 o2 signal delay.. the truck was throwin out tons of smoke under a heavy load and smelt like gas all the time i was getting about 3mpgs everywhere so i assumed that it was a o2 failure and changed the upstream sensor and everything went back to normal.. then about 3 days ago the light came on and i was getting the same codes and symptoms and instead of blowing anothr $80 i figured id look fo some help so if anyone know please help

 

sounds like a faulty sensor bring it back to the store and bugggg out

 

then run sea foam to clean that monster

 

kinda thought thats what it was since i got it from napa ive never bought a part there that didnt fail in the first week unless it was oil or plugs ha

 

can you actually see the difference when you use the seafoam

 

Yes!


Also make sure there isn't any fluids leaking on the harness of the O2 sensor and check the connections at the harness.

 

when the light came on i pulled the clip off to make sure it was clean it did have an oil residue on it so i sprayed it with some elec cleaner and nothing changed do you think it shorted out?

 

Yes!

Thats a classic!

 

sounds good thanks a lot