o2 sensor or cat?
Thread Starter
Launching!
Joined: Dec 2005
Posts: 237
Likes: 1
o2 sensor or cat? After scanning my car at autozone, i get the code: "P0420 Catalyst System Efficiency Below Threshold (Bank 1)". is there a way to tell if its the cat or the sensor (maybe like a "seat of your pants" feeling?). Does this code only come up from a clogged/malfunctioning cat, or can a dirty/broken o2 sensor cause this too? i asked this in another thread, but i figure this will help others with the same problem too. hopefull daily driving with this code wont be bed for my car, just until i get it fixed
TECH Senior Member
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
I'd switch the rear 02's side to side, clear the codes, then see if you get P0430 for the passenger side. If it moves it's the 02, if it doesn't it's the cat. Remember the cats are covered for 8yrs/80K.
Launching!
Joined: Dec 2005
Posts: 225
Likes: 0
From: S. JerZ
I got the same reading from autozone, took it to my mechanic and he told me it wasn't the o2's it was the car. Now im trying to figure out if I can just buy 2 replacement hi-flow magnaflow cats and have them welded in place (dual cat)
