S4 idle issue

slob · 01-08-2021, 10:11 PM

It’s a bit of both.
The ECU has a ‘map’ which tells the injectors how much fuel to deliver based on sensor readings for engine speed, throttle position, air pressure, temperature etc.
Flashing the ECU loads a new map. A Power commander sits between the ECU and injectors and applies preset changes to the map, so if you can flash the ECU directly the PC is effetively obsolete.
There’s still room for fine tuning (stock or modified map) either based on exhaust gas analysis or dyno readings. A basic map based on your state of tune, eg. open filter and pipes, will put the settings in the right ballpark but a full setup will almost always get you closer to ideal settings. You get what you pay for.

01-08-2021, 10:11 PM	#11
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,715	It’s a bit of both. The ECU has a ‘map’ which tells the injectors how much fuel to deliver based on sensor readings for engine speed, throttle position, air pressure, temperature etc. Flashing the ECU loads a new map. A Power commander sits between the ECU and injectors and applies preset changes to the map, so if you can flash the ECU directly the PC is effetively obsolete. There’s still room for fine tuning (stock or modified map) either based on exhaust gas analysis or dyno readings. A basic map based on your state of tune, eg. open filter and pipes, will put the settings in the right ballpark but a full setup will almost always get you closer to ideal settings. You get what you pay for.