why is my service suspension light on and i keep getting a code po121 i replaced my gas cap canister gas pedal and my auto start want work but when the code is gone it works if i take the

Asked by Feb 22, 2015 at 01:06 PM about the 2008 Chevrolet Avalanche

Question type: Maintenance & Repair

when I take the neg cable off it will auto start but after a few mile the code comes back and the auto start will not work   code p0121

1 Answer

805

On my 2009 Avalanche, there was an emissions sensor that went bad. I tried all the things you did, which worked for a while then the check engine light came back on. Before I took it to the garage, I lost power at the transmission - pedal all the way in, RPMs to the red and 40 mph, on a major highway. ... it was ~$800 to fix the sensor & flush transmission fluid. Runs like a champ now. Might be worth having your mechanic take a look. Hopefully it's not as expensive a repair as I had.

Your Answer

Chevrolet Avalanche Experts

  • #1
    Tom Demyan
    Reputation
    300
  • #2
    David Scott
    Reputation
    170
  • #3
    Oscar Leon
    Reputation
    150
View All

Related Models For Sale

Used Chevrolet Silverado 1500
2,712 Great Deals out of 174,045 listings starting at $955
Used Ford F-150
3,311 Great Deals out of 220,937 listings starting at $1,200
Used Chevrolet Tahoe
822 Great Deals out of 41,881 listings starting at $1,987
Used Cadillac Escalade EXT
25 Great Deals out of 621 listings starting at $3,900
Used GMC Sierra 1500
1,253 Great Deals out of 64,571 listings starting at $999
Used Dodge Ram 1500
439 Great Deals out of 11,107 listings starting at $1,995
Used Cadillac Escalade
268 Great Deals out of 11,899 listings starting at $1,200
Used Chevrolet Colorado
348 Great Deals out of 37,994 listings starting at $1,595
Used Toyota Tundra
705 Great Deals out of 34,260 listings starting at $1,500
Used GMC Yukon
621 Great Deals out of 20,760 listings starting at $2,600
Used Toyota Tacoma
725 Great Deals out of 45,388 listings starting at $1,000
Used Chevrolet Suburban
502 Great Deals out of 24,088 listings starting at $1,799
Used Dodge Charger
466 Great Deals out of 33,534 listings starting at $1,999
Used Chevrolet Silverado 2500HD
403 Great Deals out of 30,551 listings starting at $2,995

Used Cars For Sale

2013 Chevrolet Avalanche For Sale
7 Great Deals out of 462 listings starting at $11,946
2012 Chevrolet Avalanche For Sale
6 Great Deals out of 259 listings starting at $11,000
2011 Chevrolet Avalanche For Sale
19 Great Deals out of 501 listings starting at $10,800
2010 Chevrolet Avalanche For Sale
10 Great Deals out of 268 listings starting at $11,300
2009 Chevrolet Avalanche For Sale
7 Great Deals out of 326 listings starting at $10,535

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.