marjh

my check engine light is on and when i give it gas to accelerate the check engine light flashes. when i let of the gas and it slows down the light just goes back to steady on. it runs a little rough and idles slightly rough. the first timei pulled the codes it said random miss fire, and the second time it just ssaid cylinder #1 miss fire. i replaced the fuel filter and check spark plugs they seem fine. could it be just bad gas?? it still has power and help would be great thanks

silverado122775

How many miles do you have on the truck? Did you inspect your plug wires?

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2000 Silverado Z71, 5.3L, K&N GenII Air Intake, Y-pipe Exhaust (no muffler), Bosch Platnium +4 plugs.

marjh

i have 103000 roughly and it just started one day, no i didntbut the wires are new from last year, but i will check

silverado122775

Make sure the wires are not touching anything that get's hot and can melt the wires. The other thing it could be is the MAF sensor going bad.
Have you done any mods to your truck?

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2000 Silverado Z71, 5.3L, K&N GenII Air Intake, Y-pipe Exhaust (no muffler), Bosch Platnium +4 plugs.

taillight

Pull your trouble codes.

marjh

i pulled the trouble codes and it just says random miss fire then the second time i pulled them it said miss fire on number one cylinder but the random miss fire is what makes me belive its just gas but who knows and no i havent done any mods besides kn airfilter.

Sonny01

Did you recently re-oil the K&N filter?

intel_guy

I had a random misfire code whenever it rained(the truck also ran really badly). I recently noticed that there was a broken ground cable on the driver's side firewall. I'm thinking this was shorting out somewhere when it was raining. I re crimped, re attached and taped it and have not had the symptom since...

ranger2751

I am having the same problem replaced plugs and wires also messed a bit with the coils. No luck. Keep me in the loop if you figure it out. I know mine is not fuel related

xjcamaro89

Ive seen this sort of problem with the s-10 blazers, pull the MAF sensor and check all the tiny tiny wires in it that the air flows over, sometime they get covered in black gunk and then they dont read the air right, if they are dirty, take some carb cleaner or paint thinner and a q-tip and very carefully with the lightest of touch and get that black gunk off. Make sure your are very careful, those little wires and very fragile and if one breaks your screwed. Take a look at it and let us know.

rjeffery

Your MAF sensor can also get fouled if you over-oil your K&N, or don't let it dry for long enough before re-installing it. I think you can buy MAF sensor cleaner or do like xjcamero89 said.

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2002 1500 Ext. Cab 4.8L 2wd.
K&N FIPK, Cat Back Exhaust, Rancho RSX Shocks, Silverstar Headlights High & Low, Infinity Reference Door Speakers & 10" Dual Voice Coil Sub. 265/75/16 BFG AT/KO's, Spray-In Bed Liner, Hella FF75 Fog Lights, Hella FF75 Driving Lights.