engine has mis?

1999 Silverado 2500 6.0L I have a hesitation problem or a misfire i'm really not sure. Sometimes when at idle it will just drop like it lost half power to one cylinder you'll fell it for a split second and also when hard in the gas from a stop sign it will stumble and spit until you let of the gas. I have ran a couple tanks of gas with techron fuel injector cleaner and have also put heat in the tank (wisconsin weather). The service engine light has not come on so i'm thinking it's not computer realted.

I have a 4.8 in my 99' that does the same thing, I noticed it most when it sits for awhile. but im almost thinking it was cause by condensation traped in the gas tank. do you often let the gas run under a 1/4 tank?? or haven't filled it completly up in awhile?? might be a small cause.

I have a 4.8 in my 99' that does the same thing, I noticed it most when it sits for awhile. but im almost thinking it was cause by condensation traped in the gas tank. do you often let the gas run under a 1/4 tank?? or haven't filled it completly up in awhile?? might be a small cause.

you know that's what i thought because it did sat alot this summer with gas prices up so i have been putting heet in the tank and it is still doing the same thing i changed the fuel filter about 4-5 months ago.I think it is a clogged injector or two just the way it acts when you really get in the gas it spits and sputters then finally goes it does idles fine.So i'm trying injector cleaner foe now then will go with the shell v power gas and try it.

let me know how thay V-power works, cause if its worth the extra 20 some cents extra, i'll have to try it

Hi, you might have an oxygen sensor problem. I had a similar situation with my '00 Silverado, I gave her a tune up and replaced the pre-cat o2 sensors and now she runs like new. However, you could also be having problems with your fuel pressure regulator or a coil pack.

I'd recommend going to an auto parts store and borrowing their code reader. This will allow you to see if anything comes up and then you can run a search on the codes on the Web.

Just a fyi-- I replaced the plugs and wires now it runs like new. Thanks guys for the help. mike