Just bought an '02 L 13K miles. Have it for about 3 weeks now. I've noticed a hollow humming sound that wasnt there the 1st week. Also yesterday i took it out to really feel the power. On my way back home while in traffic there was a lot of engine flutter while standing still. The same when in P.
The throttle response has decreased a little as well.

Admittedly not an auto guy, need your input!

 

Id first change the fuel filter and plugs...

 

you probably got a coil pack bad check 3 & 4 I've had to replace #4 twice and recently #3

 

it's weird how #3 and #4 coils like to go bad on these trucks, while the #7 and #8 spark plugs like to go bad.

regarding the spark plugs, someone once noted the shape of the plenum and the entire entake that might affect this.

....and I ramble



-Mike

 

Thanks, I figured these would have been possible solutions.
What about the deep hollow sound!