Jay Don

How many miles on your car? How long have you been experiencing the light? I'm not sure what all can be damaged by not replacing this immediately but I was under the impression that it was only needed to pass emissions etc. I know these things can be very expensive though. He said you need 2? It looks like the car has 2 oxygen sensors so thats what the code might be showing.

I know this doesn't help but my 2001 GS 430's check engine light is on as well. It will appear periodically because I have a 2800 rpm performance torque-converter. Does the light ever turn off?

Someone help this guy! I would be interested too. :)

I have 115,000 miles, once in a while the light may go off but it comes back. Don't the O2 sensor have a different code

My engine light on my 2001 GS430 is on. When I went to the mechanic he told me the computer say it is PO420 Catalyst Efficiency Below Threshold bank 1 and 2, and that each convertor would be $1,250 each. My car runs excellent so it was hard for me to believe that it could be bad. Can anyone tell me were to find a cheaper catalyic convertor or can it be the sensors.

My engine light on my 2001 GS430 is on. When I went to the mechanic he told me the computer say it is PO420 Catalyst Efficiency Below Threshold bank 1 and 2, and that each convertor would be $1,250 each. My car runs excellent so it was hard for me to believe that it could be bad. Can anyone tell me were to find a cheaper catalyic convertor or can it be the sensors.