Quote:
Originally Posted by trblmkr
As for basic intake mods, as long as the MAF is reading the correct volume of air entering the engine and the fuel system can keep up, wont the standard ecu keep AFR's in check? |
In a word NO the stock
ecu can't keep the afr's in check.
The
ecu is programmed to use the
maf signal output as the load reference for the fuel map. Changing the volume of the air column before the sensor and you run into issues where the
ecu will swing lean or rich due to either laminar flow in the piping (why long CAI's cause lean out) or turbulent flow past the sensor (why pods mounted to the
maf cause slightly richer afr's).
The above is why a MAP sensor is the better way of getting a load reference,
MAF's can be fooled - MAP's can't.
The only other feedback the stock
ecu has is the narrowband oxygen sensor which is only used for cruise mixture trimming for emission control & economy.