Engine light on in 09 pontiac g6


Asked by Sep 23, 2013 at 07:32 PM about the 2009 Pontiac G6

Question type: Maintenance & Repair

I have a 2009 Pontiac G6 (4 cylinder) that has the engine light turned on. I went to an auto parts store and they told me the catalyst efficiency had a low bank because the o2 sensors monitor the catalytic converters ability to store oxygen and the possible causes were the catalytic converter was defective due to engine misfire or running condition, there's a large vacuum leak, or the engine oil leakage into exhaust-valve guide seals, piston rings. I have no idea what any of it means, if anyone could guide me in the right direction, I would really appreciate it. Thanks.

3 Answers


Having the 4 digit code would better help us. The tech is partly right, but having the code will tell us which O2 sensor is detecting the problem. Do you have a misfire? The codes would tell us which coil was the problem and if you have a vacuum leak as well. Post the code or codes and we'll get back to you.


The troubleshooting code is P0420

2 of 2 people found this helpful.

ritzy24, If you are still having concerns and would like for your GM dealership to look into this further, please let us know. You can email us at socialmedia@gm.com. Erica Tiffany GM Customer Care

2 of 2 people found this helpful.

Your Answer


Looking for a Used G6 in your area?

CarGurus has 3,784 nationwide G6 listings starting at $1,250.


Pontiac G6 Experts

  • #1
  • #2
    Norm Davis
  • #3
    Andy Huhn
View All

Related Models For Sale

Used Pontiac G8
14 Great Deals out of 421 listings starting at $4,500
Used Pontiac Grand Prix
11 Great Deals out of 2,574 listings starting at $1,750
Used Chevrolet Malibu
1,067 Great Deals out of 63,700 listings starting at $880
Used Chevrolet Impala
547 Great Deals out of 35,140 listings starting at $990
Used Ford Mustang
567 Great Deals out of 37,028 listings starting at $2,595
Used Nissan Altima
1,126 Great Deals out of 80,161 listings starting at $1,500
Used Dodge Charger
360 Great Deals out of 30,729 listings starting at $2,000
Used Ford Fusion
965 Great Deals out of 65,185 listings starting at $888
Used Toyota Camry
966 Great Deals out of 91,756 listings starting at $300
Used Honda Accord
1,124 Great Deals out of 67,234 listings starting at $561
Used Pontiac G5
5 Great Deals out of 425 listings starting at $1,495
Used Chevrolet Camaro
475 Great Deals out of 31,741 listings starting at $1,450
Used Ford Focus
758 Great Deals out of 58,161 listings starting at $1,150

Used Cars For Sale

2010 Pontiac G6 For Sale
5 Great Deals out of 170 listings starting at $3,499
2009 Pontiac G6 For Sale
25 Great Deals out of 651 listings starting at $1,250
2008 Pontiac G6 For Sale
12 Great Deals out of 954 listings starting at $1,700
2007 Pontiac G6 For Sale
7 Great Deals out of 1,026 listings starting at $1,999
2006 Pontiac G6 For Sale
5 Great Deals out of 766 listings starting at $1,900

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.