Why is my GMC Sierra idling high when I come to a stop?

2000 GMC SIERRA
212,500 MILES
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TYLERCOVELL
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I have a 2000 GMC Sierra 1500 5.3 and i recently changed the IAC and the TPS and cleaned the egr and maf sensors and it fixed the problem of rough idling and sputtering. Now after doing all of that sensor work it now feels like the throttle gets stuck when i slow down and come to a complete stop. When I'm at a stop the truck sits at roughly 1200 rpms for at least five seconds and then it will go back to the normal idle. Why would it be doing that?
Sep 8, 2012 at 2:19 AM
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SATURNTECH9
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Have you checked for codes yet?
Sep 8, 2012 at 3:46 AM
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TYLERCOVELL
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Well it's not throwing any codes at all.
Sep 8, 2012 at 12:51 PM
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SATURNTECH9
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Lets try this remove the negative battery cable for one min then hook it back up.See if that works sometimes all you have to do is give the computer a little reboot like when your cell phone acts up and you turn it off and on again.Let me know what happens.
Sep 8, 2012 at 3:07 PM
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TYLERCOVELL
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Ok so I tried that and nothin changed... Now I was thinking, I did clean the throttle body and replaced the gasket, could a vacuum leak from the new gasket not sealing properly possible cause it to act that way?
Sep 9, 2012 at 1:23 AM
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SATURNTECH9
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The only reason I wasn't thinking a vacuum leak was because it idles down after a few seconds. It wouldn't hurt to look for a vacuum leak.Also.how is the coolant temp sensor?
Sep 9, 2012 at 2:35 AM
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TYLERCOVELL
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I changed that about 6 months ago and alright I'll check and get back with you
Sep 9, 2012 at 4:13 AM
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SATURNTECH9
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Alright keep me posted.
Sep 9, 2012 at 5:25 AM
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TYLERCOVELL
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So I have been driving the truck and it still does it but I notice it only does it with the ac on.
Sep 13, 2012 at 7:48 PM
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SATURNTECH9
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Does the idle kick up when turning on the ac?
Sep 13, 2012 at 8:43 PM
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TYLERCOVELL
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When the truck is sitting still at idle and I turn on the ac it fluctuates every so often like every 45 seconds it's will rev a up from like 600 rpms to about 700 to 750 and drop back to 550-600
Sep 13, 2012 at 9:43 PM
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SATURNTECH9
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Could be a vaccuum leak have you looked for one?
Sep 14, 2012 at 5:17 AM
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TYLERCOVELL
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No I haven't, how can I do that?
Sep 14, 2012 at 1:55 PM
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SATURNTECH9
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Before that have you tried cleaning the idle air control valve?
Sep 15, 2012 at 3:58 AM