what makes my 04 gmc sierra run rough,pop through exhaust,and pop a po300 code

Asked by May 14, 2014 at 10:31 PM about the 2004 GMC Sierra 1500 2 Dr STD 4WD Standard Cab LB

Question type: Maintenance & Repair

Po300 popped up and I changed the plugs and wires...reset the code and the next day its
comes back on...took to a shop they said to change plugs and wires and 02 sensor...did
all that with same result...now they tell me I got a bent valve...someone told me to change
the crankshaft positioning sensor which I did and after the truckwouldnt start....so I put
the old one back in and it runs but like shit....please help

1 Answer

Thanks for nothing

Your Answer

GMC Sierra 1500 Experts

  • #1
    dragonflyoffshore
    Reputation
    5,500
  • #2
    John Saffrahn
    Reputation
    3,780
  • #3
    Glenn Clingenpeel
    Reputation
    3,500
View All

Related Models For Sale

Used Chevrolet Silverado 1500
2,873 Great Deals out of 162,468 listings starting at $1,500
Used Ford F-150
3,159 Great Deals out of 223,315 listings starting at $1,000
Used GMC Sierra 2500HD
104 Great Deals out of 13,577 listings starting at $1,950
Used Chevrolet Silverado 2500HD
420 Great Deals out of 29,435 listings starting at $2,000
Used Toyota Tundra
664 Great Deals out of 34,086 listings starting at $1,500
Used Ford F-250 Super Duty
464 Great Deals out of 46,641 listings starting at $595
Used Chevrolet Tahoe
837 Great Deals out of 39,683 listings starting at $1,990
Used Toyota Tacoma
662 Great Deals out of 41,053 listings starting at $2,500
Used Dodge Ram 1500
376 Great Deals out of 11,010 listings starting at $1,800
Used GMC Yukon
553 Great Deals out of 18,615 listings starting at $1,950
Used Chevrolet Colorado
397 Great Deals out of 38,478 listings starting at $1,995
Used Jeep Grand Cherokee
1,061 Great Deals out of 66,904 listings starting at $950

Used Cars For Sale

2018 GMC Sierra 1500 For Sale
28,497 listings starting at $23,886
2017 GMC Sierra 1500 For Sale
92 Great Deals out of 6,823 listings starting at $19,999
2016 GMC Sierra 1500 For Sale
146 Great Deals out of 3,870 listings starting at $15,500
2015 GMC Sierra 1500 For Sale
192 Great Deals out of 5,817 listings starting at $14,995
2014 GMC Sierra 1500 For Sale
233 Great Deals out of 4,810 listings starting at $8,495

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.