Get yourself an AFR meter!

Needsaresto, interresting link you posted there!

Reading that article, this is obviously for a narrow band sensor. The issue with narrow band sensors is that they are only accurate around 14,7 AFR, or stociometric. Apart from telling you if you are lean or rich relative to stochiometric, you can't rely on any ratios outside of that.

But having said that, even with this limitation, being able to tell if you are running rich or lean is certainly better than knowing nothing at all! A possible excemption to this is if you run very rich to the point of getting incomplete combustuion, this can be misinterpreted as a lean condition since unburned oxygen will be present in the exhaust.

Based on my personal experience, I would go for a wide-band solution any day, those extra dollars are really well spent and really not much compared to the time, money and effort most of us invest in our hobby.

Me, I'm running just a sensor and a sensor driver (You can't just hook up a wide-band sensor to a voltmeter or any other external device like you can with a narrow-band unit) which then feeds a voltage analogue to the AFR to my megasquirt unit. So when I hook up the laptop for some tuning or simply to see what's going on, I get a dial on the screen showing the AFR.

I bought an Innovate LC1 package of e-bay for about 130$, really not much compared to what just the sensor costed only a few years ago.

http://www.innovatemotorsports.com/products/lc1.php

Obviously, if you don't run an EFI set-up, you need a set consisting of the wide-band sensor, a driver unit, and a gauge.

You can allso get the same kit with a suitable gauge, and Iæve seen this for as little as arround 170$ on e-bay. Allos great value in my opinion.


http://www.innovatemotorsports.com/products/db.php

There are probably other solutions available, but Innovate seems to be quite serious stuff and seems to get a lot of positive feedback in the various EFI and DIY communities.

When wide-band sensors first started becomming available, the sensors alone could cost as much as 600$ (if my memory serves right). Building a working driver from scratch and calibrating the set-up was allso fairly involved and required an aptitude for electronics slightly above average..

Just how affordable and available wide-band sensing technology has now become is really a DIY tuning dream come true.