Pontiac Repair: Engine idle is high, throttle position sensor, power brake booster

Question
I have a 1999 Pontiac Grand Prix GT and the engine is a 3.8 V6. I just
recently changed my Throttle Position Sensor and the idle is really high
and I just changed a few other parts to see what was wrong like my spark
plugs and wires and I had to replace my catilytic converter. But I thought
that would be all I needed to do. Is there a specific way the Throttle
Position Sensor is suppose to be put on?

Answer
Hi Jimmie:

did you have the idel problem before or after the TPS was replaced. The TPS is a major input to the engine control module for engine spped. So if you don't have it on right or if the one you put on was a fits all then that is the reason why. An original equipment TPS has no adjustment. when you put it on your all set. An aftermarket one may need to be adjusted the problem there is if you don't have a scan tool there is no way tell if it's adjusted/put on right. That engine the tps reading should be just under or just at .40 Volts much higher it will cause a higher then desired idle. Also a vacuum leak can cause a high idle as well take a look arounf and see if you see any vacuum lines plit or missin. That engine has a vacuum tap back by the hose for the power brake booster. Good luck :)