0 like 0 dislike
426 views
by

2002 Buick Regal GL 3.8L with code P0420 light came on

Vehicle: 2002 Buick Regal GL 3.8L

1 Answer

0 like 0 dislike
by (13.5k points)
HI there,

This code stands for catalyst efficiency below threshold. This basically means the bank 1 catalytic converter isn't able to clean the exhaust like it should. Most of the time a new converter is required to resolve the code.

That being said, you can also have an issue with the rear O2 sensor cause this code, as well as a poorly running engine and an exhaust leak.

Related questions

0 like 0 dislike
1 answer 415 views
0 like 0 dislike
1 answer 219 views
0 like 0 dislike
1 answer 208 views
0 like 0 dislike
1 answer 269 views
0 like 0 dislike
1 answer 751 views

36.2k questions

32.2k answers

1.3k comments

22.8k users

Need A Repair Shop?
Find local automotive repair shops in your area.
Does your car have Safety Recalls? → Check here
...