5.3 motor question

[Acommanderguy]

Alright so I am a little stumped and my mechanic I think is just being really lazy. So here let me pick some of your brains. I have a 2000 tahoe lifted 6 inchs on 35's with the 5.3 liter in it. Great truck runs solid. Anyways I recently had a tune up down plugs oil change fuel fliter K and N fliter etc... Anyways My truck has a freaking misfire! My mechanic thinks its the the plugs. (Bosch platnuim plugs)
Changed them to the autolight plugs same result. It kinda likes to sputter at low temp then I let off the gas, and reapply it. runs fine. If I put it in park and press on the gas peddle to make it hit 900 rpms you can hear a slight pop/backfire. Grrr making me mad. I asked my mechanice could I have an arching wire? he said let me check, pulls on the wire and says oh they seem fine.
I am sick and tired of sitting at idle and the damn truck has a small shake to it!
Also has anyone had any issues with an evap sensor? its causing me check engine light to come on

[NOTALENT]

Alright so I am a little stumped and my mechanic I think is just being really lazy. So here let me pick some of your brains. I have a 2000 tahoe lifted 6 inchs on 35's with the 5.3 liter in it. Great truck runs solid. Anyways I recently had a tune up down plugs oil change fuel fliter K and N fliter etc... Anyways My truck has a freaking misfire! My mechanic thinks its the the plugs. (Bosch platnuim plugs)
Changed them to the autolight plugs same result. It kinda likes to sputter at low temp then I let off the gas, and reapply it. runs fine. If I put it in park and press on the gas peddle to make it hit 900 rpms you can hear a slight pop/backfire. Grrr making me mad. I asked my mechanice could I have an arching wire? he said let me check, pulls on the wire and says oh they seem fine.
I am sick and tired of sitting at idle and the damn truck has a small shake to it!
Also has anyone had any issues with an evap sensor? its causing me check engine light to come on
I would switch back to the original AC Delco plugs, make sure there gapped correctly. The code for the check engine light....is it just reading the one code for the evap sensor?

[Acommanderguy]

Ya its just reading the one code. A few hours after the new plugs were put in the truck ran great. The next day started doing the same crap all over again. I am thinking maybe a wire arching. The lights goes off and on.

[HighRoller]

One thing you can do is pull off your air intake tube and clean out your throttle body/throttle blade. Those engines tend to get a nice dirt buildup which leads to poor throttle response. It's a coil per cylinder arrangement so you might have a coil acting up.

[Acommanderguy]

if a coil was acting up though wouldnt the scan tool find it? or have a code for that? its not showing any problem except for the evap code.

[79Challenger]

One thing you can do is pull off your air intake tube and clean out your throttle body/throttle blade. Those engines tend to get a nice dirt buildup which leads to poor throttle response. It's a coil per cylinder arrangement so you might have a coil acting up.
I think you are on the right track here. Did you put a factory replacement K&N or a FIPK? Both, when over oiled, can allow the excess oil to be sucked onto the MAF sensor and cause all kinds of strange symptoms. The FIPK is more prone to this, but I have seen the factory replacments do the same thing.
Might want to pull the MAF and take a look.

[robsformula]

could be a hair line crack in the dist. cap. When its cold runs fine then when a little heat builds up the cap could exspand a hair and cause a miss fire. Or you could even have a bad wire. Are they carbon wires?

[voodoomedman]

Go back to the original AC Delco plugs like stated before. I changed the plugs on the little cavalier and had that problem even though I got some super cool four point plugs from Autozone. The dealer put AC Delco's back on and it ran fine. They said it could be the heat range or something like that. The other thing to keep in mind is that on GM you don't need to even change the plugs till 100,000 miles. I figured it would be better to do it before but the dealer told me there was no need and I shouldn't have touched it til then. Pricey mistake.

[BowTie Rick]

I think you are on the right track here. Did you put a factory replacement K&N or a FIPK? Both, when over oiled, can allow the excess oil to be sucked onto the MAF sensor and cause all kinds of strange symptoms. The FIPK is more prone to this, but I have seen the factory replacments do the same thing.
Might want to pull the MAF and take a look.
Urban legend. We have sprayed oil directly onto a mass air sensor from a paint spray gun and it does not hurt it. We have test equipment that the dealerships don't even have and I can guatantee you that cannot happen. Everything we have had sent to us from customers that had dealers tell them it was the K&N has been either working just fine or internally shorted at the plug connection. We've even taken a far share of dealerships to court on behalf of customers and we are batting 1000.

[Wet Dream]

Does that use one COP (coil over plug) per cylinder, or one coil per 2? Either way, they don't always trigger a misfire code. The cylinder seems to have the need to have several several several consecutive misfires before it will trip a code. Although I have a Ford, a few minutes of non firing finally trips a code. A spark every other or every 3rd stroke seemed to maintain the integrity of the computer and showed nothing. Mine would be fine until it got warm, and then misfire. I plugged in my reader and got a bad COP D (#4). Cleared the codes, still acted up but never tripped the code or CEL. Replaced #4 COP and its all good now.