ASPX Wide Band

A couple of things to note about A/F guages, and some of it has already been mentioned here.
I paid around 160 or so for mine and LOVE it.
It will allow you to set your mixture at all rpm's without guess work or having to pull plugs to check how they are running. (of course pulling a plug or two is a nice verification of what the guage is telling you.)
On my own car, for instance I will end up getting the next size up needles for the Edelbrock because I am a little on the rich side in the normal midrange of my throttle, and just a hair rich on WOT.
I may also accomplish this with smaller primary jetting, but the point is that I can make that adjustment even though it probably would not even be noticable while driving the car.

One other thing I would like to mention, is that just because 14.7 to 1 is the perfect chemical mixture it doesn't mean you can run the car at that mixture.
Idle quality starts going downhill at about 14 to 1 at 180 degrees (worse if the engine is colder)
And around 14.7 to 1 an engine under load will run too lean and hot.
Don't take the 14 to 1 too literally or you won't be very happy about how your engine runs.
In my own case over a few months my car seems to like around 13.5 or so in all ranges of throttle. (1 point leaner than what would be considered perfect as far as optimum chemical mixture)
My idle mixture is currently at almost exactly 14.7 to one and the car doesn't idle right until it gets up to 180+ degrees. (lean misses) until fully warmed up.


Most kits are single sensor kits and they tell you that you can add a bung to each side and swap the sensor from side to side when checking the total A/F ration of the entire engine. (of course this requires a plug for the unused side, or two plugs if only used to tune and then removed)
Crackedback (Rob) mentioned that the wideband sensors MUST be powered (in use) whenever they are in the pipe.
This is because they are a heated sensor and without the heat the exhaust buildup on the element will ruin the sensor.

The A/F guages have other advantages that you will find out later on.
The one I have also shows error codes, so one night I was downtown and the guage started flashing a E9 error (which is a low voltage code)
I pulled over and found my field wire had popped off the alternator, so I crimped it tighter and put it back on and the problem went away. (i might not have noticed the guage in time before the battery was to low)

The other advantage I found was that I was driving along one day and as I stepped on the gas the engine hesitated a little.
One look at my A/F guage showed the engine went lean at that moment.
I had fairly new filters, enough fuel, and a clean tank so I knew it was the electric fuel pump so I picked one up while I was downtown.
2 days later my fuel pump died, but I already had a replacement in the trunk and 10 min later it was back on the road.

They make a great time cutting tune and diagnostic tool if you notice what it tells you, and know what the solution is.


Sorry for the long wind, but most of this is what I didn't know until I started using one so hope the info helps others.