I have a 99 tl. About the past 3 weeks the motor has been cutting in and out around 4500-6000 under full throttle in 1st and 2nd. It will sputter in and out until it shifts and gets into lower rpms then does it again until it hits 3rd. I don't know if there is trash in the fuel or what. ANY help appreciated. This car is beginning to be a curse

 

That sounds like the car going into limp mode for a second..
Do you have a check engine code?

 

Could be EGR related.

 

Could be a foul plug or bad coil, etc.

 

start with the basics
air filter, egr system INSIDE of intake manifold cleaned correctly?
spark plug age and brand?

ck all ground wires, have electrical system tested free at parts stores

any rotten egg smell?