What can contribute to a P0420 fault code (Catalyst System Efficiency Below Threshold)? Beside faulty CAT(s)...
My D1 has thrown a P0420 code twice in the past two months. New Y-pipe/dual CATs were installed ~11 months ago, to replace the original Y-pipe when the bank-1 CAT blew it's guts out - causing a loud rattle and blowing exhaust sound. This failure also resulted in a P0420 code! Present replacement exhaust sound fine, but the code returns...
So, am I unlucky with CATs, or are there other issues I should check out first?
I may swap the bank-1 O2 sensors with the bank-2 sensors to see if the fault code also jumps from bank-1 to bank-2.
Regards,
Tom P.
My D1 has thrown a P0420 code twice in the past two months. New Y-pipe/dual CATs were installed ~11 months ago, to replace the original Y-pipe when the bank-1 CAT blew it's guts out - causing a loud rattle and blowing exhaust sound. This failure also resulted in a P0420 code! Present replacement exhaust sound fine, but the code returns...
So, am I unlucky with CATs, or are there other issues I should check out first?
I may swap the bank-1 O2 sensors with the bank-2 sensors to see if the fault code also jumps from bank-1 to bank-2.
Regards,
Tom P.