I have a random misfire code still after replacing a whole bunch of stuff!

Asked by Feb 24, 2017 at 01:03 PM about the 1998 GMC Sierra 1500 C1500 SLE Extended Cab SB

Question type: Maintenance & Repair

i have replaced my spider injecton, plugs and wires, distributor, cap and rotor,
new cats. the egr seems to work fine the pintle thing moves in and out pretty
good unless its not supposed to do that! the only thing i havent done is replace
coil and o2 sensors.

1 Answer

77,815

Possible causes; Faulty spark plug (s), Faulty ignition coil (s), Clogged or faulty fuel injector (s), Intake air leak, Fuel injectors harness is open or shorted, Fuel Injectors circuit poor electrical connection, Ignition coils harness is open or shorted, Ignition coils circuit poor electrical connection, Insufficient cylinders compression, Incorrect fuel pressure...Cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs. If the problem persist more tests needs to be done to diagnose problem.

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
169 Great Deals out of 10,258 listings starting at $2,230
Used Ford F-150
637 Great Deals out of 9,058 listings starting at $1,995
Used Ford F-250 Super Duty
29 Great Deals out of 664 listings starting at $1,790
Used Chevrolet Tahoe
5 Great Deals out of 776 listings starting at $4,200
Used Toyota Tacoma
25 Great Deals out of 1,189 listings starting at $4,444
Used Dodge Ram 1500
40 Great Deals out of 451 listings starting at $3,488
Used GMC Yukon
4 Great Deals out of 850 listings starting at $4,995
Used Chevrolet Camaro
927 listings starting at $12,498
Used Jeep Grand Cherokee
137 Great Deals out of 3,741 listings starting at $2,995

Used Cars For Sale

2018 GMC Sierra 1500 For Sale
7,664 listings starting at $30,468
2017 GMC Sierra 1500 For Sale
17 Great Deals out of 649 listings starting at $26,938
2016 GMC Sierra 1500 For Sale
19 Great Deals out of 277 listings starting at $20,988
2015 GMC Sierra 1500 For Sale
55 Great Deals out of 521 listings starting at $19,995
2014 GMC Sierra 1500 For Sale
50 Great Deals out of 419 listings starting at $16,291

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.