98 Tacoma 2.7 runs a bit sluggish - any suggestions?

A snapshot during the event with a scan tool might show the root cause. Remember the RPM drop is the effect, not the cause. Monitor all the sensors that use a 5V reference to look for any unwanted low/high voltage issues. You can also use a good DVOM with the min/max feature to monitor a circuit. Also, it's always a good idea to check all the grounds and connectors for corrosion, especially on vehicles that have been sitting.

 

It does have an egr, and the new throttle body came with a tps attached. I have my old one and could swap them. Not something I have tried yet

 

TPS is new, came with throttle body. it does have EGR. the ERG does appear to function properly, but I do not know how to test if its causing the problem.

 

Leave the TPS on the new throttle body, the egr... just disconnect the vacuum line on the valve, plug the vacuum line and test.