I have an 02 yukon xl. longtube headers, flowmaster super 40, dual 3 inch pipes K&N CAI. Replaced the spark plugs a few thousand miles ago and double checked to make sure the gap is set correctly and the wires are okay. At idle, every few seconds i get a noticeable pop in the truck that almost sounds like the engine is skipping a beat. from a stop the engine accelerates like it is out of round until around 5 mph then it feels fine. after 130,000 miles i figured it might be the fuel filter so i swapped it out. i want to say that it is happening a little less often now, but ive noticed it a few times. should i give it more time to flush some fuel through the engine or should i flush the whole fuel system or does anyone else recommend a way to diagnose the problem?
Idle Slight Misfire Feeling.
- Thread starter ekordas
- Start date
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Thumper8302
Full Access Member
hey eric i know what your goin thru... have you checked the inside of your throttle body... like the butterfly? i have an 01 kon with almost 240xxx on the clock and after i did an induction cleaning it was smooth as a baby's ass... with you also runnin a k&n i would get some mass air flow sensor cleaner and give the sensor a good spray down every 3-4 months since you have an oiled element..... I still have yet to do a tune up on mine and ive owned my kon for just about a year with adding only 9xxx miles on the clock.... but changing my fuel and air filters and cleaning out the throttle body and maf sensor has helped out considerable... u may wanna do a search on runnin 2 cycle oil in the gas.. i have heard and read alot of great reviews on that... hope this helps ya out man... gotta love our works in progress lol
Rivieraracing
Full Access Member
Might be in need of some new spark plug wires or possibly a new coil pack!
doubletapdrew
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After you've tried the above suggestions if you still have the problem make sure all your spark plug wires are firmly seated on both ends, and check your spark plugs for cracks. It's very common to accidentally crack the insulator on the spark plug while installing long tube headers and it causes that exact same problem.
Turns out it was my intake manifold. It had an internal leak. If you have above 100k miles I recommend replacing it. GM poorly made these and they warp really easily. I bought the newly designed one from
Carquest for $295. My idle is smooth and I immediately noticed an increase in power.
Carquest for $295. My idle is smooth and I immediately noticed an increase in power.
Rivieraracing
Full Access Member
Glad you found your problem and were able to fix it!! How did you end up finding that out?
Well I replaced everything the code wanted and it still came up. I did the smoke test for a vacuum leak and it was fine. Every mechanic I talked to said these have very common internal leaks so I replaced and luckily it fixed the problem. Even if I didn't have a problem, it would be good to replace it. Truck drives like brand new!
