what does the code 402 mean in pontiac grand am gt 2002

Asked by Nov 10, 2012 at 03:51 PM about the 2002 Pontiac Grand Am GT

Question type: Maintenance & Repair

I have changed both upstream and downstream o2 sensors and installed a new thermostat and then cleared the codes,, 2 days later service engine soon light light comes on with code 402...Could this be the catalytic converter ????    I hate to spend the cash if this is not it,, please help me if you can kevin k thankx

1 Answer


Let me guess auto zone told you that the code meant the O2 sensors were bad so they could sell you 2 $80 sensors? P0402 has nothing to do with a bad O2 sensor its caused by excessive egr flow and the link takes you to a site that will explain how to diagnose what exactly it is so you don't have to throw parts at it. http:// www.obd-codes.com/p0402 feel free to reply to this post if you need more help, I will get an email on my phone within 20 minutes of your reply and I will get to it once I have a few free minutes.

1 people found this helpful.

Your Answer:

Pontiac Grand Am Experts

  • #1
  • #2
    Tom Demyan
  • #3
    John Saffrahn
View All

Related Models For Sale

Used Pontiac Grand Prix
14 Great Deals out of 1,774 listings starting at $800
Used Pontiac Firebird
6 Great Deals out of 679 listings starting at $4,700
Used Ford Mustang
261 Great Deals out of 37,615 listings starting at $1,350
Used Chevrolet Camaro
239 Great Deals out of 27,310 listings starting at $2,077
Used Chevrolet Malibu
482 Great Deals out of 51,491 listings starting at $1,975
Used Chevrolet Impala
372 Great Deals out of 25,650 listings starting at $950
Used Nissan Altima
735 Great Deals out of 66,647 listings starting at $1,499
Used Honda Accord
565 Great Deals out of 103,291 listings starting at $950
Used Toyota Camry
757 Great Deals out of 72,781 listings starting at $1,000
Used Pontiac Bonneville
330 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.