really high idle on start
Possibly vacuum leak or dirty/faulty idle air control valve. Could also be pcv valve stuck open.
If there's no Check Engine light, you could try removing the IAC Valve and clean it and the throttle body. Disconnect the battery for 5 minutes and reset the computer. The best approach would be to hook up a scan tool and watch the pids to see if it's actually the computer or an outside influence (as dandyoun suggests).
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