71-Camaro-98

iTrader: (17)

I popped a SES light yesterday on my 98 and I had it read at checker and the guy said the code was P420. He explained that it was either a cat or an O2 sensor that had gone bad... Any suggestions? In the end I think my car is just telling me it is ready for headers

2001NBMZ28

P0420 usually turns out to be the cat (drivers side). You could try switching the rear 02's side to side and see if it throws P0430.