Almost sounds like a TPS acting up. While your driving highway speeds, your foot isnt really moving on the accelerator. If you floor it does it still fluctuate rpms? Also, did it do this prior to the tranny being replaced? May be a speed sensor issue. Also, when was the last tune up done? Plugs, wires, fuel filter play a big act in how a car performs. Is the check engine light on? If so, have it scanned by your local parts store, and let me know what codes if any show up.
Thursday, September 2nd, 2010 AT 10:39 PM