Re: Very hesitant 166 2.0ts
Mitch do a search on the forum,
but in short. (and I assume this applies to TS as well as V6)
1.Disconnect battery, short red and black wires to discharge any residual current. This will clear your ecu of any "learnt" mapping.
2.Reconnect battery. Turn key to MAR position, don't start engine.
You will hear throttle whirring and moving, leave it for a least 90 secs to do this. Turn key to off, leave another 90 secs, then start engine BUT DO NOT TOUCH throttle at all, wait until engine up to operating temp ie fan on/gauge up then turn off.
I suspect you can reset throttle without ecu reset but may be wrong.