Buick Lesabar Misses when climbing hills no engine lite

My Buick Lesabar Misses while climbing hills. There is no engine light to direct me to the problem. Just a shot in the dark but could it be a VSS or TPS.

This sounds more like secondary ignition breakdown; i.e. coils, wires or plugs

Yup, secondary ignition. Look around the coil terminals, where the metal stud comes out of the coil housing. If there is a black residue, that coil is likely bad.

I have a 2000. Mine has 76,000 miles. On a random basis, it seems to miss going up a slight incline. It now has the same type of miss at a stoplight. Engine feels like it's about to cut off but does not. Mechanic already replaced the coil two weeks ago. The missing problem continues. Mechanic can not isolate problem in diagnostics. Any suggestions?