I took my car in (1999 Pontiac Grand Am, 2.4 L) got a code for the Throttle Position Sensor. Replaced that, same thing happened. It would hesitate when I accelerate and the trac off light would come on. Along with my service engine light. Took it back to have the codes ran and it popped the same code for the throttle position sensor. So again I replaced that and the piece that connects. Spliced the wires. Went back and it still ran the same code. Already replaced the spark plugs, and fuel filter. Any help would be greatly appreciated. Another thing I noticed is that it idles at 600 RPM, and the throttle body barely opens up when the car is at 2500 RPM. 

On 3/24/2019 at 6:58 PM, Badge68 said:

I took my car in (1999 Pontiac Grand Am, 2.4 L) got a code for the Throttle Position Sensor. Replaced that, same thing happened. It would hesitate when I accelerate and the trac off light would come on. Along with my service engine light. Took it back to have the codes ran and it popped the same code for the throttle position sensor. So again I replaced that and the piece that connects. Spliced the wires. Went back and it still ran the same code. Already replaced the spark plugs, and fuel filter. Any help would be greatly appreciated. Another thing I noticed is that it idles at 600 RPM, and the throttle body barely opens up when the car is at 2500 RPM. 

These types of problems are difficult to consult on without being there, but with what you seem to consistently discribe I would look at the following. Make sure the are no issues with the wheel sensors, both physically and electiclly.

Also look at induction, not spark or fuel injection, but air, both the electronics and mechanicals surrounding that system, I.E. throttle body, wear, broken or bad return springs. Gummed up throttle shaft or plate or just plain carboned up. You might even see if you can get a used one and replace yours to see if that effects it. Check the IAC sensor, doubtfully, but possible. Vacuum leaks, check all hoses that are vacuum hoses, including the PCV!