08 Silverado 5.3 high idle issue

[choptop]

Ok guys, I have a problem and am looking for help/advice. My work truck, 08 K1500 with the 5.3 is having idle issues. I believe i caused it, just not sure how. Heres the story. I am approaching 100k on the truck and had a code for the tps. Last time it logged the code, the Chevy house cleaned the throttle body, and sent it back. This time, I cleaned it. I disconnected the battery, and removed the air inlet piping. Cleaned the throttle plate and housing with throttle body cleaner, and re assembled everything back. Started it up, it idled ok, reved it up a bit and it went up to 2500rpm and stayed. I have checked and rechecked everything I took apart, and all is back in place. WHen it throttles up, if you turn it off and restart it, it idles back about 600 rpm as normal. I took it for a little trip at 55mph for about 10 miles ( I was told to do so to let the tps relearn) and as long as i let it idle down while in gear, its fine. If I put it in neutral, and tap the throttle, it goes to 2500 rpm and stays.

 A little more info, with my scanner, i monitored the throttle readings" foot is off throttle pedal in all readings. IAT was reading 44 degrees, pulled it cleaned it, read.89 degrees. 65 degrees outside
when normal                                 when acting up
rel tps=5%                                      rel tps-15%
tps b-19.2%                                    tps b_29.8%
accel pedl b-19.2%                           accell pedl b-19.2%
accel pedl D-9.4%                             acwll pedl d-9.4%
command-8-9%                                command 21.7%
600 rpm                                           2530rpm

Any help would be greatly appreciated

[choptop]

oh, one more to add. WHen it idles high for the short time before I shut it off, it will log a PO507 code.

[roadrage41]

idle air control or a vacuum leak

[Irish_Alley]

you prob know of this site but here it is anyway
http://www.obd-codes.com/p0507
A P0507 DTC trouble code may be caused by one or more of the following:

A vacuum leak
Leaking air intake after the throttle body
EGR valve leaking vacuum
A faulty positive crankcase ventilation (PCV) valve
Damaged/failed/dirty throttle body
Failed EVAP system
Failed IAC (idle air controller) or faulty IAC circuit

now know what you did to it i would think it still has to do with the throttle body. i would clean it again and double check everything

[choptop]

Ok, truck is fixed so I thought Id post in case someone else came across the same thing. I had my throttle relearned and everything went back to normal.
 It was explained to me that as the throttle body gets dirty, the ecm makes adjustments. WHen the throttle body is cleaned, it is a sudden change and the ecm doesnt know what to do. He said it would readjust back to normal after 150-200 miles of driving since the GM electronics learn how to adjust settings based off of your driving habits. In short, if you clean your throttle body on a newer DBW GM, have access to a Tech 2 scanner that can aid in relearning the TPS or be prepared to make a 150 mile road trip.

[zieg85]

Glad you got it figured out