Q on O2 Wires, and MAF Position

[Dale]

Finally got my idle figure out, now onto other things.

1. I am wanting to mount a dash AF gauge for driving. It says to hook it up to the signal wire. Duh. But it list wires as heater+, heater-, signal-, signal+. The wire diagrams for my system(express van) say heater+, heater-, HO2Hi, HO2Lo. Do I need to hook upto the hi, or the low?

2. Due to some changes in my setup. I had to rotate my MAF sensor 90 deg so that the plug didnt hit some other crap. Will this change its reading any?

[joecar]

1. The NBO2 signal switches from below 300mV to above 700mV at about 3-10 Hz... does your AF gauge know this...?
I don't think it's good to tap off the NBO2 signal because the gauge will "alter" the NBO2 signal.
The NBO2 signal is on hi wrt lo (lo is the signal ground; lo may or may not necessarily be referenced to vehicle ground, it may be floating depending on vehicle/PCM... the PCM may be biasing lo to ~4.5V, and the NBO2 then rides hi wrt to that).

2. It is fine to rotate the MAF (it doesn't rely on gravity assist ).

Cheers,
Joe

[Dale]

1. This is the gauge I got ahold of. And not for that price either http://www.iequus.com/product_info.p...ory_id=100_105

How will it alter it? Because it may draw power from the signal?

2. I know it wasnt gravity controlled. But I was wondering if that splitter in the middle may deflect the air a certain direction and having it in a different way may change the airflow across the sensors.

[thunder550]

Putting a gauge on a NBO2 is pretty much worthless...it won't tell you anything other than you're running at stoich, which the PCM will do anyway as long as the fuel trims are turned on. If you want to know how your vehicle is running, you need a wideband.

[joecar]

Sorry, I was only kidding about GA...

The splitter is to route air around the element support so that the support doesn't cause turbulence...

Yes, it would draw power from the NBO2 signal and distort it...

What Tunder said... some widebands like the LC-1 two outputs, one for WB AFR and the other for NB signal...

With V2 BBL coming along, you will be able to do this with the LC-1:
- serial output AFR -> V2 logging,
- analog output 1 -> NBO2 signal,
- analog output 2 -> AFR gauge (LC-1 can be reprogrammed)

[Dale]

I'll hook it up a temporary way and see what it does. For the price I got the gauges I figure it was worth it. Would help me diagnose which side has misfire or is acting up.

[TAQuickness]

I'll hook it up a temporary way and see what it does. For the price I got the gauges I figure it was worth it. Would help me diagnose which side has misfire or is acting up.

It probably was. Although the NB's are inaccurate off stoich, if you go WOT and the NB AFR gauges goes all the way lean, you can bet you have a problem. They are a good quick visual to indicate the fueling conditions.