So, I filled my car up with Optimax, and as per in the knowledge page....
Advice to reset the reading of higher octane fuel for the ECU to read and record under driving characteristics, and aid throttle response etc...............

I took out my 20amp ECU fuse, I went to take out my 15amp ETCS fuse and it wasnt even plugged in. (I had been noticing that my "ECT PWR" button when presed and displayed on the dashboard, there was no noticable acceleration difference from standard). I put this fact that there was not ETCS (electronic Throttle control) in operation due to the lack of fuse not plugged in.....

So, I waited 30 seconds, i plugged back in the ECU fuse, and this time, took a spare 15amp fuse and plugged it in where the ETCS 15amp fuse should be....

When using ECT PWR button now, I have a bigger kick on acceleration (Ithink-it's marginal)Prob due to the electronic throttle now being controoled by the fuse now plugged in.................(Is this how it works, I dont know)

BUT------When driving, I can smell a slight whiff of burnt exhaust gases through my air intake in the cabin after plugging in the fuse...to confirm this I have removed the fuse, and now the exhauset gas smell has dissapeared.

I have auto transmission and a six cyl engine.

Question1.
Can any one eplain how ETCS works, and what the fuse regualtes, and what I was missing out on with the fuse not plugged in. And what gain I expected/results to see, with the fuse now plugged back in.

Question2.
Why did the burnt exhaust smell appear (im my opinion) when the ETCS fuse was plugged in, with the fuse in also, I noted a slightly wobblier acceleration.....

Question 3.
Do i have a fault with the ETCS fuse plugged in, ands is that why someone had removed it prior to me buying the car?

Question4.
What harm will occur with the ETCS fuse removed, or does it simply just not make the ECT PWR switch not work. What does the ETC PWR button actually do, as it doesnt appear to be much.

Thankyou.

anyone please?

The pwr button should make the gearbox hold gears for longer under normal driving. e.g. instead of changing gear at 2500rpm it may change at 3000.

Full throttle acceleration doesn't make any difference as both modes that the engine to redline.

The ETCS is not for the pwr button it is the electonic throttle control. Does your engine warning light not come on with this fuse removed? If not then does your engine warning light come on at all? (turn on ignition without starting the engine)

Yes, engine light does come on with fuse out when key turned in "ignition mode"
before starting car. Then does go out when engine is started.

But this fuse replaced, coupled with exhaust smells concerned me.

engine appears smoother with fuse out, wobblier with fuse in.