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


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
  • #2
    John Saffrahn
  • #3
    Glenn Clingenpeel
View All

Related Models For Sale

Used Chevrolet Silverado 1500
196 Great Deals out of 12,408 listings starting at $1,700
Used Ford F-150
683 Great Deals out of 14,025 listings starting at $3,000
Used Toyota Tacoma
40 Great Deals out of 1,166 listings starting at $7,950
Used Dodge Ram 1500
55 Great Deals out of 509 listings starting at $3,488
Used Chevrolet Tahoe
7 Great Deals out of 826 listings starting at $3,995
Used Ford F-250 Super Duty
28 Great Deals out of 978 listings starting at $2,475
Used GMC Yukon
9 Great Deals out of 967 listings starting at $2,500
Used Chevrolet Camaro
941 listings starting at $12,000
Used Cadillac Escalade
4 Great Deals out of 549 listings starting at $4,980

Used Cars For Sale

2018 GMC Sierra 1500 For Sale
8,186 listings starting at $29,040
2017 GMC Sierra 1500 For Sale
18 Great Deals out of 1,923 listings starting at $399
2016 GMC Sierra 1500 For Sale
31 Great Deals out of 287 listings starting at $22,995
2015 GMC Sierra 1500 For Sale
70 Great Deals out of 592 listings starting at $20,998
2014 GMC Sierra 1500 For Sale
41 Great Deals out of 467 listings starting at $17,482

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.