2002 Other Chevrolet Models 4 cyl Automatic
my check engine light was on. It came back as code
po420 catalyst system efficiency below threshold
bank 1 so I had a new catalytic converter put on
a month later my check engine light is back on with the same code
any idea why? I also had the 02 sensor replaced
have the same problem?
Saturday, October 11th, 2008 AT 2:49 PM