I need to buy a gauge so i can see if my car is running rich or lean whitch gauge is the most accurate? I would like to get the phantom gauge to match the rest of my gauges in my car.

 

I believe most of the O2 meters on the market use a standard O2 sensor, so they are about equal. Remeber, the O2 sensor is not linear, it just tells you that your either rich or lean from stoich (14.7:1). It CAN NOT tell you how rich or how lean.

Now, if the O2 meter uses a WIDE BAND O2 sensor, then it can tell you accurately how rich or lean you are. But expect to pay more for these units.

I have built my own O2 Air / Fuel meters, and I am surprized at how simple they are, and how inaccurate they are.

If the Air/Fuel meter is designed to work with your factory O2 sensor, then it is not a wide band sensor.

Don't get me wrong, I think an air/fuel meter is a great addition. Just be careful how you interpret the information.

On another note, I am not sure if you can really splice into your existing O2 sensor without degrading the signal to the ECM. I still have to do some measurements on my own setup to see, but I expect there would be some impact.

Mark.

 

when you say wide band 02 are you refering to a 3 wire o2 sensor or heated. I don,t want a sensor that just looks good. What might be a better tool or sensor to buy for tuning etc.besides a 2000k scanner. Can i use some of those devices alot of lt-1 owners use? I think scanmaster is one of them.

 

A heated O2 sensor only helps the sensing element get up to it's operating range(about 600F) more quickly. This is important with headers, which dissipate a lot of the exhaust heat. Until the O2 sensor reaches it's operating temperature, the ECM cannot go into closed-loop mode. However, the heated sensor still has the same narrow-band of sensitivity as the OEM unit(only accurate very near stoich - 14.7:1 air/fuel).

A wide-band sensor - as it's name implies - has a much broader range of sensitivity. These units can sense as rich as 9:1 and as lean as 18:1. This allows you to trim the fuel much more accurately across the engines operating range, i.e.,... leaning the mixture in response to increasing rpms. Because of the very limited range of the OEM sensor, at WOT the ECM adjusts the fuel for max flow and the ignition for max advance. This protects the engine, but means you lose power on the top end(when the A/F should be leaned, and the ignition retarded).

The wide-band sensors have 2 failings.
1. You need an ECM that can recognize, interpret and respond to the wide-band's output correctly. The OEM and some aftermarket ECM's are designed for the narrow-band sensor.

2. The wide-band sensor is many times more expensive than the OEM(expect to pay $600+).

------------------
He who hesitates,... is lost!