Motor has 49,400 2002 buick century and the service engine light is on. Any other complaints or problem that are known. Local mechanic shows a code 420 but told me to take it to a GM dealer. Looking for additional owners with similar problem
Cars & Trucks - Buick - Century
Answers & Comments
I agree w\tripleauto
YOUR code is a catylyst efficiency below threshold.
what this means is the computer is seeing the catylitic convertor is not doing its job.
gm has an 8/80 warranty on the convertor you should be covered by that