Hi, my car's been having this issue where as soon as it's at operating temp and the fast idle stuff shuts off, then the idle hunts from 700-1000rpm. So far I have adjusted the TPS, and although it did help massively, it didn't fix it entirely. Any ideas?

 

welcome to the board.

check/change the water temp sensor on the back of the water pump.

 

the S5 has rpm targets at idle, and if you're too far out it can't compensate and you get the surging.
if the TPS is right, try adjusting the idle air screw, its right on top of the throttle body.

you're supposed to adjust it to 750rpm with the service connector jumped, this turns off the timing compensation.
however you can also get a timing light and adjust the idle screw until the timing is correct. ie once it hits the target idle speed, the timing will be right on the marks.

 

Alright, I'll try that. Thanks a ton, I appreciate it!

 

Alright. Thanks for the help, appreciate it