The ECU is exactly that , Engine Control Unit also called ECM Engine Control Module and in some cases a PCM Powertrain Control Module which incorporates engine and transmission control.
The ECU controls the engine operation with the input of around a dozen different sensors so I guess the question would be, what idle issues are you having, too high, too low or wont idle at all ?
what size exhaust?
there was issues with 3" exhausts that would hit because its a real tight fit and it has to be fitted just right.
if its a stock exhaust then i suspect its another issue. it should not hit no matter how bad the engine vibration is.
According the mechanic it's 3" inch and it's knocking at a flexible joint that has fine wire mesh wrapped around it and you can see the rubbing on the mesh.
Had a look in the "You Beaut" workshop manual and there are some sensors that send messages to the ECU for idle control so, I think before I started removing the ECU, I might suss out where the sensors are and replace on a trial an error job.
Thanks for the help anyway fella's
sounds like the flex joint is in the wrong place. they are a bit bigger than the pipe so it needs to be placed somewhere where there is more room.
3" is a little bit big and you have to get it just right to fit it without knocking.
otherwise post up a pics of the exhaust system.
Mine was rattling but after running a fuel/injector cleaner through it, no more rattle and much smoother but took two tanks to work.
Also with the 3" pipe it runs a little close to the first strut after the body on the dual cab, on another vehicle here I did make a small bracket to move the rear mount 50mm towards the centre which stopped any chance of it hitting but then took it out and bent the flare on the first strut up because I needed all the width in the spare wheel area for an extra fuel tank, both mods work ok.