I was contimplating whether or not to get an air/fuel gauge. My ECU is the M2 stage 3. With this ecu as well as the pettit, PFS ECU, would I benefit from the air/fuel gauge even though I cannot change the values of the ECU? Other than satisfying my curiosity of my air/fuel mixture how else would it be helpful to someone that has a non-programable ECU like myself?

 

really just finding out how rich/lean you're running and if its one way or another, you might decide and go out and get a pfc or something else programmabale

 

they are pretty much useless. much better to get a wideband.

 

It may be a hell of a lot better to get a wideband, but I would hardly say its useless. I wouldn't tune by it, but its a good safety measure to go by, and for so cheapI think its worth it.

 

The A/F guage only reads what the ecu sees. The stock O2 sensor is the "problem", and no matter what guage you have, its only as good as the sensor its reading from. Most narrow band A/F gauges tell you specifically not to use them for tuning purposes. I don't see why a wideband would be any better if his ecu is already tuned.

 

My point exactly. I 'm thinking whether wideband or not, having te air/fuel gauge is more or less eye-candy for those who have non-programable ECU's, right???

 

its more or less eye candy either way. i guess it works as a some sort of safety measure. but that is why i said it is, pretty much useless.

on the other hand i guess i should read more carefully being that he has nonprogrammable ecu, my suggestion to go wideband probably wouldn't help him.

 

Si.

In answer to your original question though, you don't really need an A/F guage, unless you want to see what the stock O2 sensor is transmitting.

 

Thanks Shinobix, that's what I was thinking....

 

a wideband can be a direct indication to the health of your fuel system and tune of your motor....what makes you think the A/F ratios will stay the same forever??...every engine is different and changes with time...a wideband will allow you to monitor the fuel and keep you aware of any problems which may arise along the way....i love my motor...and intend on keeping it happy for a long time....thats why i have a wideband.

 

The stock o2 sensor is only accurate around 14.7:1 which is stoich. Lean is above that on the stock sensor. By the time it reads lean, you've already blown your engine. Either get a wideband, or the greddy a/f gauge w/ the 5wire heated sensor (not a wideband but very close).

 

interesting points guys.....keep them coming...

 

Just a few questions. What fuel management system are you using? Do you have a knock sensor? Aside from tuning purposes, have you had any personal issues with detonation that have been avoided through the addition of the A/F guage? What type of driving does the car see?

A well tuned and working ECU shouldn't be a problem, and under boost you'd have to be able to watch and react extremely quickly to avoid detonation. Over the course of your engine life (properly tuned), I think it would be safe to say that your AFRs should be consistent, should you pay attention and include regular maintanence to the fuel system and engine in the first place.

 

I have a like new DEFI D-Gauge A/F looking for a new home. $60.00 shipped