Problems but no idiot light!!!

[5.7sbc]

Hey, all, seems like I have a new headache to go with this weekend. 2000 LS V8/AUTO seems to be misfiring. Problem is similar to others I've read.
At around 50 mph it stutters, goes away at about 60 but is lacking power in the pedal and running rough under acceleration. It also seems to go away with the cruise on. Car idles fine, leaks no oil, drives great below 50 mph, still gets good gas milage and the is no "check engine" light.
Can some of you guys/gals kick this around and come up with some suggestions. Just give me some things to look at or for so I can procceed from here.

 

[RequestingFlyBy]

Sounds like coils. I have a 2000 and my check engine light didn't come on for any of them (replaced all 8). I had the exact symptoms you do. If you are doing them yourself, do all 8 at once and check your valve covers. Mine was under warranty and they wouldn't change all 8 at once, so I would get one fixed and 2 weeks later another and so on. Then a month after they were all fixed, I had the leaky valve covers. Good news though, once they are all done, there are no more problems and everything runs great. Good Luck.

 

[2002_LS_V8]

still gets good gas milage

damn i didnt think that was posible with this car lol, what is it 18mpg? lol anyways looks like its coild like that guy said.:shifty:

 

[5.7sbc]

Well ya, the car is getting around 18mpg and 75% of my driving is city driving. I only notice the problem when I am on the highway. I'm gonna replace the fuel filter first and then go from there. I just can't fathom how this car with all its electronics, sensors, bells/whistles etc isn't throwing a code or check engine light.