Code 0420

I have an 02 with a 2.4L - engine light is on and the error code is 0420 - cat efficiency. I have 2 cats on this and was wondering if there is any way to diagnose if its the front, back, or both. I don't have a lot to sink into the truck right now - emissions test coming up soon too. Thanks.

 

just cause toyota put a 0 in front of it doesn't change what that code means...
Code 0420 =

 

When that code sets you can do some diagnostics to see if it is really a bad cat or something else, but with your mileage I will bet your cats are done.

You are outside of the Federal warranty on cats at 8 years or 80,000 miles so,,,,

You will need to replace your cats. Don't be fooled to think that aftermarket cats are going to be good enough. I get calls all the time from people that installed "approved" aftermarket cats and still get the P-0420 code on Toyota trucks.

Now, if you are going to use this as an off road only or racing vehicle and never register it or use it on the highways, you can keep that check engine light off with the URD Rear O2 Simulator.

G