RE: Throttle Position Sensor Replacement
I had this same problem, the engine blipping about 200 rpm during cruise control. Also, I had a surging problem at idle at the same time. The fix was new throttle position sensor and idle air control. A friend of mine who has a garage did it for about 200 bucks total. I could do it myself, but didn't have time at the time.
According to him, he got a code on it. I've subsequently gotten idle speed codes from a check engine light when I've scanned the OBDII. Either the idle air control is going out again, or I've got a vacuum leak somewhere. I'll wait until it codes differently. Otherwise, I just clear the code, because it just says engine didn't reach expected idle speed.
And my idiot dealer couldn't figure out the TPS problem either.