Fuel Map Tuning - why neccasary if 02 sensor is going to do adjust it anyways ??

[kengeroo]

...okay stupid question # 325...

just got my wideband installed

during normal operation the O2 sensor is doing it's fazz to maintain a A/F ration of 14.7

..so what's the point of tweaking the fuel map to the target map if the O2 sensor is going to take over ?

[Super_Dude]

The computer uses the 02 sensor to react and make small adjustments to the map. You want your fuel map to be as close as possible for smooth results.

If the map wasn't close and the 02 sensor was making huge adjustments your AFRs would fluctaute greatly.

Not really that stupid of a question

[kengeroo]

okay,, closed loop vs open loop,,
closed loop (engine warm and at crusing speeds or idle) is when the inputs from the O2 sensor actually do stuff to the fuel mixture...

Is there common areas in the fuel map that you can consider "open" and "closed" under general operations...

[archaeic_bloke]

also... the ECU doesnt read the O2 sensors past 0.1 bar of boost... it switches to its table values... it measure the air coming into the system by using the MAF's (Air Flow Meters) and for each mV at the MAF's it adjusts to the corresponding fuel and timing u set it for.

thats really more whats going on....