Last year I had preowned cats and new O2 sensors put it to pass smog and clear the codes. I got lucky, but P0430 just now came back on.

I dont know if the cats have gone bad again, or I wonder if the cats and O2 sensors have gotten gunked up from the engine burning oil.

Maybe try Cataclean or Oxicat???!!!

 

i tried duralube catalytic converter cleaner from Amazon and it didn’t do anything. Just a warning from real world trial and error.


i changed my o2 sensors on both sides and it fixed my problem.

 

The CEL went off, I guess my car fixed itself??!!

 

i guess?? I’ve never had the luck of seeing a CEL turn off on its own lol…

 

Try checking the exhaust clamps. The bolts could have come loose at the manifold, and mid pipe flanges.