hey guys, i hope this is in the right topic but anyways i have a 02 4.0 and i'm looking to hook up a air/fuel gage to maybe save me .10 at the pumps when i fill up. ha. but i'm not sure what wire i'm supposed to hook it up to on my computer.. i dunno if anyone has gone through this before could maybe enlighten me on this situation. any info is appreciated. thanks -Dan

 

A a/f gauge won't help you save gas. All it does is tell you if the engine is running rich or lean. If you want something to save you gas get a Scangauge.

http://www.stuffforyourranger.com/st...roducts_id=212

 

well i'm pretty much talking about when i'm towing becuase i race quads/sleds year round so if i'm going up a hill i'd like to know if i'm just wasting gas going up the hill and with little gain you know? plus i have had it laying around since my last ranger so i'd still like to hook it up

 

Like said before that A/F gauge won't help with that, it mearly shows how the engine is running. If you want to see how much load is on the engine for towing you could use a vacuum gauge, I have one on my truck and it helps show me how much i'm into the throttle and how hard the motor is working.

 

An a/f gauge still won't help you have gas. It tell you if the engine if running lean or rich which helps you if you are tuning the engine so you can add or take away fuel. The air/fuel ratio doesn't really change when you use more or less throttle.

Go for the scangauge. You could also use an economy gauge(vacuum gauge in disguise).

 

yeah the a/f guage is not going to tell you if your running rich or lean at half throttle the numbers will be so fast and inconsistant it would be pointless. like stated its mainly used for tunning at wide open throttle. you should be looking at somthing that messures load or injector duty cycle, thats mainly what fule econamy guages monitor in luxury cars.. get a scan guage i think it will tell you everything you need to know.

plus with the a/f guage your talking about (autometer a/f guage for ex..) its not going to tell you anything if your reading it off of a narrow band o2 sensor, we like to call these "light show guages". if you want a real a/f gauge (wideband) your gona have to get somthing like am AEM uego or an NGK afx wich requeires you to use a standalone o2 sensor, and they arent cheap..

 

than i guess i'm mistaken terribly but when i tow with my fathers 454 ( packed full 4 place snowmobile trailor and 1 sled in the bed ) and i'm going up a hill the a/f gage shows me if i'm going into the throttle to much and with little benefit so i'm not just putting gas into the engine thats just making it run rich...

 

An inexpensive "rich/lean" narrowband A/F meter would be perfectly adequate for finding the transition threshold from closed loop to open loop fueling. It is also easy to install.

You can use the signal wire from either of the two front sensors. Tapping in right at the PCM (passenger side firewall) offers a much cleaner, drier environment than down by the sensors. Regardless of which location you choose, these are the harness color codes:

DS: red/black
PCM pin 87

PS: gray/light blue
PCM pin 60


Autometer instructions:

http://egauges.com/pdf/AutoMeter/837j.pdf