Today, I replaced the thermostat on my 97 Lumina 3.1 with 168K miles on it. I had to remove the throttle body to do that, I noticed there was lots of carbon buildup in side the throttle body so I sprayed it with carburetor cleaner. Now, when I start the car RPM goes to 4000. Some time it drops down to 500 and shakes like its going to stall. What has gone wrong? Thanks for any help and suggestions.

Recheck your work for vacuum leaks, proper electrical connections and binding throttle linkage, also any check engine lite?

Hi Max, no vacuum leaks or throttle linkage issue, however the CHECK ENGINE light is ON. I didn't have time to go to AutoZone today, but tomorrow I will make a trip there and let them do a scan. Could the MAP sensor cause this? You think there is still some cleaner left in there?

No map will do this, get the code and post back.

ok, thanks