Is my Car High? P0420 Catalyst System Efficiency Below Threshold (Bank 1)
 

So I have been driving around on the setup below for probably about 1 year.
Over a month ago I get a CEL P0420 for the Cat. I cleared it and then about 2 weeks ago it came back. I cleared it again, and it came back 2 weeks later.

Im running stock headers, DP, and cat... I have the corsa cat back sport, and have been running it un touched for a while (maybe a year)

I have no performance issues, no loss in boost. I do get the ticking sound when my exhaust cools off. Got it from day one and it never went way... only ticks after some rough housing.

I haven't tapped in any extra o2 sensors.

What do you think... is my cat dieing as the CEL seems to be coming up more frequently?

Could it be the plugs? Or something else... perhaps time for a new fuel filter?

Thanks,
Rich

i would say it is either your cat or a sensor somewhere

usually that comes with an aftermarket DP,

maybe CEL is from 02 sensor going bad

Or your cat could have nothing in it (gutted)?

After sueing gm for warrenty issues... I was given a Major Gaurd extended warrenty to 90,500 miles.

Do you think I could try and get it fixed under warrenty?

Isn't Corsa GM brand stuff?

Thanks,
Rich

p0420 is catalyst efficency.....most likley a bad cat.

Dare I ask how much a replacement would run?

Edit: Forgot to mention, the CEL only usually comes on when I am idling.

-Rich

Just so you guys know octane booster kills cat's If your using it stop! Octane booster uses alot of phosporous which coats the cat element making it die or in the worst case it plugs the face of the cat thereby plugging the exhaust. I've seen it plenty of times and a GM engineer told me the same thing.

Hey guys im throwing this same code, and i looked under my car at the cat and there is a little pin hole in the cat. Do you think thats the reason its throwing the code? Thanks

Hey guys im throwing this same code, and i looked under my car at the cat and there is a little pin hole in the cat. Do you think thats the reason its throwing the code? I just bought the car (used) and I highly doubt there is an aftermarket exhaust on it. Thanks

Well if there is a pin hole exhaust you should feel a lot of hot air coming out when the car is on.

I take that back its not my cat its my resonator and ill have to check if its blowing air out, but would that still make that code go off?