on my 2011 3/4 silverado hd, I have a yellow engine light on. The codes are 174 and 496. MAP and o2 sensor. The only sysmptoms I'm getting are when the fuel cap is removed ther is a vacuum whoosh. The the vehicle is hard to start. Sounds like the evap purge valve. Not sure but never had one cause a vacum. Ive seen pressure, so i guess it could go the other way as well. help

Asked by rhopman Mar 30, 2016 at 07:56 AM about the 2011 Chevrolet Silverado 2500HD LTZ Crew Cab 4WD

Question type: Maintenance & Repair

2011 Chevy Silverado HD 3/4 ton

2 Answers

102,915

If your EVAP purge valve is bad, it should have also thrown a code. If you would like to test it yourself follow the link below. A hard start is a symptom of a bad purge valve, especially after you fill up at the pumps. http://www.samarins.com/glossary/purge-valve.html

2 people found this helpful.
102,915

You may want to first repair your error codes before pulling your purge valve to test it. A bad MAP sensor will cause fouled plugs and a rich fuel mixture which could be the cause of your hard start issues. Fix the codes first, then check your purge valve.

Your Answer:

Own this car?

Share your experience with others.

2011 Chevrolet Silverado 2500HD

Review another car

CarGurus Experts

  • #1
    GuruXPQGJ
    Reputation
    1,430
  • #2
    Reelin68
    Reputation
    1,190
  • #3
    Steven Loeffler
    Reputation
    1,150
View All

Know more, shop wisely

Search

Related Models For Sale

Used GMC Sierra 2500HD
525 Great Deals out of 23,104 listings starting at $5,990
Used Chevrolet Silverado 1500
4,205 Great Deals out of 127,028 listings starting at $1,987
Used Ford F-250 Super Duty
1,290 Great Deals out of 44,595 listings starting at $2,799
Used RAM 2500
995 Great Deals out of 47,248 listings starting at $3,500
Used Chevrolet Silverado 3500HD
366 Great Deals out of 10,634 listings starting at $5,600
Used Dodge RAM 2500
47 Great Deals out of 1,071 listings starting at $3,995
Used GMC Sierra 1500
1,970 Great Deals out of 69,014 listings starting at $2,999
Used Ford F-150
6,199 Great Deals out of 144,235 listings starting at $1,500
Used GMC Sierra 3500HD
230 Great Deals out of 7,605 listings starting at $9,995
Used Toyota Tundra
1,144 Great Deals out of 34,253 listings starting at $3,500
Used Ford F-350 Super Duty
842 Great Deals out of 23,192 listings starting at $4,995
Used Chevrolet Tahoe
1,235 Great Deals out of 24,156 listings starting at $1,300
Used RAM 3500
439 Great Deals out of 19,076 listings starting at $12,795

Used Cars For Sale

2024 Chevrolet Silverado 2500HD LTZ Crew Cab 4WD For Sale
36 Great Deals out of 3,227 listings starting at $57,411
2023 Chevrolet Silverado 2500HD LTZ Crew Cab 4WD For Sale
34 Great Deals out of 269 listings starting at $47,773
2022 Chevrolet Silverado 2500HD LTZ Crew Cab 4WD For Sale
29 Great Deals out of 316 listings starting at $44,988
2021 Chevrolet Silverado 2500HD LTZ Crew Cab 4WD For Sale
19 Great Deals out of 212 listings starting at $34,900
2020 Chevrolet Silverado 2500HD LTZ Crew Cab 4WD For Sale
20 Great Deals out of 250 listings starting at $33,750

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. Content will be removed if CarGurus becomes aware that it violates our policies.