trouble code PO420?????

what does this code mean? i have replaced both o2 sensors and a few others as well as the catalytic convertor trying to get rid of this code. any insight?

Reply to
sunfire28
Loading thread data ...

Dumb question, have you cleared all codes from computer after working on car?

Reply to
Mike

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.