Whenever my car has not been driven for several hours, it idles rough. The RPMS start at about 1500-2000 and it takes about 3-4 min of warming up to go down to 1000 RPMS. Also, my car used to jerk when I started accelerating (about 20+ mph). The old owner said it was probably the TP sensor that was causing it so I had it replaced w/ a used sensor since they don't sell them new. My car still idles rough and kinda still jerks. But it feels a lot more powerful. Do you guys think my mechanic didn't install the TPS properly? or maybe something else is causing it? or is it just normal like my mechanic said?

 

Check your ECU, are you getting a TPS code?
If your mechanic just stuck it on without setting it then it probably is causing your problem, ask him if he set the voltage or not.

 

Yes, my mechanic checked the ECU and got a TPS code. I think he did set the voltage but I'll ask him to make sure.