I have changed a bunch of parts and now it runs worse

2008 PONTIAC GRAND PRIX
125,000 MILES
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BROOKS1952
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Warning light on my 2008 Pontiac Grand Prix Reduced engine power, I have replace with new parts the Throttle Body and the Pedal Assembly. It is now runs worse than before I replaced parts. I have taken to local mech. and now to a dealer and still no fix I have replaced with new AC Delco parts, mech. says its bad pedal assembly, dealer says bad Throttle Body, one says it needs to have comp. re-set and other says its plug and go
May 5, 2012 at 1:00 PM
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HMAC300
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the computer will reset itself as you drive. scna for codes if either one of those are no good or acting up it will set a code. however a gaspedal code will not show up on an auto parts scanner you need a pro model for that. try cleaning the throttle body with choke cleaner on both sides as well as iac hole see if that helps you.
May 5, 2012 at 1:29 PM
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BROOKS1952
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Parts are all new, had it scanned at dealer yest. I bougth the throttle body on line for $180 and bought Pedal assembly at dealer and of course dealer is saying that its the Throttle Body.
They are even suggesting that I try and put old one back on. I am afraid to drive to far it dies when you have to stop.
May 5, 2012 at 1:36 PM
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HMAC300
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was the codes cleared after the part was installed? you could put the old one back on but also check your fuelpressure, it may be low.
May 5, 2012 at 1:40 PM
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BROOKS1952
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Had fuel pump pressure checked and was fine. Not for sure if dealer cleared old codes but they had it on scope so I assume they did. Also the cruise control does not work is this part of the TPS problem?
May 5, 2012 at 4:27 PM
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HMAC300
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ya the cruise control needs the tps to work to work itself. you'll have to rescan it then and see where the problem lies. it cold be a bad connection/broken wire at pcm or tps or whatever is giving the code.
May 5, 2012 at 6:22 PM
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DREW23503
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Brooks1952 did you ever find the solution to your prob..cause im in the same exact situation bought the same parts you did ,and still having the same problem.reduce engune power,no speed when I take off,cant go faster then 75 mph,and boggles down when at a stop or reversing.please let me know
Aug 6, 2012 at 6:55 PM