[Thlad]

Is there any way to change ur air/fuel ratio other than a tune??

[jussagt]

Unfortunately no there is not. Essentially when you add a bigger MAF & Bigger Injectors.. the engine is getting more Air & Fuel but the computer used to the stock tune (Air/Fuel Ratio) so their for you need to have the computer re-tuned to the new mods and correctly adjusted.

Our cars are pretty hard to tune do to the new computer they put in the cars but their is a nice program / setup for the Do-It-Yourselfs. Its Moates Quarter Horse. Very nice program, and an excellent price. Out the door with everything you need is right around $350-400 compared to the $700 Anderson PMS system that lacks a few features the Q.H. program has.

[Trick Tuners]

The QH is a sweet DIY option, but it is probably "over the heads" of the non tech savvy guys. You can use fuel pressure as a hack way of altering the AFR, but the question is why do you need to change it?

[Thlad]

its way to rich since i put the bigger injectors in. i figured the mas would fix it... it did help but i can still smell it when im idling at a light

[Trick Tuners]

You can use the fuel pressure as a hack way to get everything back in line. Take the stock injector #/hr rate over the new #/hr rate and then multiply that by 39 to get your new psi.

Ex. 19/24= 0.792
0.792x 39psi = 30.9psi.

So set the FPR to 30.9 psi and it should get you close. This will "work" as long as you don't go wild with the injector size. Tuning is always a better option because the fuel atomizes better at higher psi. I would try not to ever go lower than about 30 psi.

You should also read this for info on closed loop fuel control by the stock 02 sensors.
Open and Closed loop Fueling and Fuel Trims - Trick Tuners Forums
The stock sensors can deal with up to about 25% correction for all part throttle AFR calculations. Once you get past that limit it will ignore the maf and run off the stock tables (so it will be even richer!).

[Thlad]

Ok thanks a lot for the info!!