Anybody Else Seen This Code?

jabartram · 09-30-2005, 11:33 PM

P0420---Catalyst efficiency below threshold (bank 1)

my Esi isn't working so i cant look it up.

10-01-2005, 12:38 AM

Have you ever had a intake gasket problem? Any coolant getting into your combustion chamber can seriously screw up an O2 sensor. Another thing could be the amount of flow you have. Headers and high flow exhaust can make an 02 "freak out" sometimes as well. Did this happen at WOT? Might be nothing to worry about, unless you want to get an O2 bypass so you don't have the problem again.

-Alero- · 10-01-2005, 10:05 PM

perhaps a deletion of the o2 in the cat. and a wideband in the upstream o2? that would help out

10-03-2005, 02:10 AM

It means the O2 sensor after the catalytic converter on bank 1 is saying your cat isn't working like it should be.

brim · 10-03-2005, 11:18 AM

Quote:

Originally posted by j_smith@Oct 3 2005, 06:10 AM
It means the O2 sensor after the catalytic converter on bank 1 is saying your cat isn't working like it should be.

Quoted post

what he said