I recently replaced LIM & TPS & had all codes cleared. A few days later the engine light came on. Had it scanned & recieved code p0507. The car was running still running good so I drove it to work the next day. When I started it up the idle was high--2k rpm. I drove it about 2 miles & when I came to a stop sign, I turned it off & restarted it. The idle returned to normal. Thhis afternoon I started it & the idle went to 3k-3.5k rpm. I drove it a short distance then cut it off. It returned to normal. Is it the IAC? Is there a test for this?