Would it be possible to get better gas mileage with an adjustale FPR and lower the fuel pressure or will the ECU compensate and open the injectors more? And if that is the case, would disconnecting the O2 sensor and then lowering the fuel pressure kind of override the ECU?

I'm looking to get as much fuel mileage I can with my accord since it's my commuter. I don't need much power, just highway driving to work and back.

 

im not sure about the truth.. however, in the process of boosting my car i bought one before i started the setup and lowered the fuel pressure.. i forgot the psi i had it at.. it wasnt super low but i was getting better city mileage.. around 28-30 mpg

 

by leaning out the air/ fuel mixture you will make the combustion hotter and will be harder on the piston head. Don't do it.

 

Just curious, when you say disconnect the O2, do you mean put in a dead one? Or a block off bolt?

I think the secondary O2 is just a failsafe if the first goes out, but also does some sniffing. If it was disengaged or something wouldn't it pick up too much 02 and try to add fuel to compensate?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by awdgsx96 &raquo;</TD></TR><TR><TD CLASS="quote">Just curious, when you say disconnect the O2, do you mean put in a dead one? Or a block off bolt?

I think the secondary O2 is just a failsafe if the first goes out, but also does some sniffing. If it was disengaged or something wouldn't it pick up too much 02 and try to add fuel to compensate?</TD></TR></TABLE>

By disconnecting the O2 sensor, I mean by the wire harness. It will through a CEL and will be running in Open loop mode and will not use the O2 sensor.

I guess running too lean would run hotter, but I will pay attention to detination and won't run so lean that everytime I apply throttle I detinate. I'm not boosting this motor after all. I guess I will just have to try it and find out.

Thanks everyone.

 

the second o2 sensor is more important than the first. If im not mistaken (and I have boosted my accord). the first o2 sensor helps to monitor the EGT and mixture. the second sensor tells the ecu if the cat converter is working. if you disconnect either one it will throw your car into an open/closed loop mode...whichever one pushes more fuel into the car. i would reccomend cleaning up your fuel delivery (injectors) and optimize your timing to get the best fuel economy. right now mine sucks...i think its why they reccomend going OBD1 when boosting an OBD2 car.

 

you want the short answer?

NO

you want the detailed answer?

your injectors need a certain pressure range to properly atomize the fuel. too low and it does not do it as well too high and same thing happens.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by YeuEmMaiMai &raquo;</TD></TR><TR><TD CLASS="quote">you want the short answer?

NO

you want the detailed answer?

your injectors need a certain pressure range to properly atomize the fuel. too low and it does not do it as well too high and same thing happens.</TD></TR></TABLE>

Well that makes sense, but what if you use an Apexi SAFC to control the injector duty cycle and leave the fuel pressure normal?

 

if your hell bent on doing this make sure you have some way of measuring your AFR and/or EGT. running lean is what blows engines up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pos_cd5 &raquo;</TD></TR><TR><TD CLASS="quote">if your hell bent on doing this make sure you have some way of measuring your AFR and/or EGT. running lean is what blows engines up.</TD></TR></TABLE>

Well it is an NA engine still. I'm not gonna run boost so it wouldn't be so bad, I'd have to be hearing detonation for 10min straight before anything happens I'm pretty sure (ran an engine really lean for a few years when I was a teenager). I have an autometer af gauge and at least it will let me know when I'm stoich and really, really, really lean.

 

do you have a wideband 02 or still using the stock narrowband?

 

Just a narrowband. I know the thing is far from accurate, but I thought it was pretty accurate at checking for stoich conditions (14.7:1 afr).