Not all DTC’s will set the check engine lamp. For the check engine lamp to be set, several times each drive, it must mean you have an issue that has logged DTC’s.
So have you actually checked for diagnostic codes? Did you understand the DTC’s you are getting? Simply clearing DTC’s without understanding why they were raised and correcting the problem can be rather detrimental to your engine/driveline.
In
@Dozza ‘s case, he had a tune, he didn’t have any DTC’s, he also replaced his throttle body and accelerator pedal to no avail as he still has the problem
Since in Dozza’s has 0% APP reading and a 17-30% spiking TPS, it seems the ECU is doing the up throttle on its own volition. Other than cruise control, I didn’t think the ECU would ever command more throttle except to increasing idle for cold starts and/or when aircon is on and loading up the engine.
So clutching at straws, maybe you’d need to check/log the various temp sensors used for cold start idle up and check the HVAC (ecu) control logic to see if either is intermittently commanding the ECU to kick up the idle... Also not sure how auto down change works and whether TCU can in some instances command the ECU to up throttle before it does a downshift.... (And if it’s manual, which it’s not), no idea how launch control works and whether something on that side could also play up...)
Resolving this will require much more information on how the system actually functions than what is stated within the workshop manual
It’s probably going to need specialist knowledge lots of hours and lots of data logging to get to the bottom of it
