hey Jim I looked at the installation instructions and the AEM WB kit has a heated O2 sensor. The specifications are:

Bosch UEGO LSU4.2
1.2 amps @ 12v heater current
Warm-up time <20 secs

Would this suppress the heated O2 concern? I am asking this in the case that I do decide to experiment with emulating the NB signal.

 

Hi

My 86 16V S2 had no sensor at all as no cats, but my X-Pipes had the hole for a sensor blocked off....so I fitted the Bosch WB sensor that comes with the Uego AND ITS FITS FINE...even though I thought there would not be enough space above the X...but there was plenty and didn't even have to drop the X Pipes....

All the best Brett

 

I concur with Jim Corenman's comments. I use a TechEdge WBO2 and it has worked fine for a couple years and 12k miles on my GT. The problems Jim related to the NB simulated signal from the WB driving the LH to one limit during warm up is true and caused me a lot of head scratching until I figured it out. Keep the regular NB feeding the LH and put in another bung for the wide band. It doesn't have a measurable effect if you have the sensor in the center (8 cyls) or on one side (4 cyls).

 

So it wouldn't even matter if the sensor was a heated one or not? Wiring to a gauge first and then emulating it from there would create a latency and foul up starting mixtures then.

 

Both sensors must be heated. The WB sensor can't be used directly as the stock NB sensor can be used. The WB sensor has to be run through a control unit. The output of the control unit can go to a gauge for wideband display, or the NB simulated output of the WB control unit can go to the LH. Some WB gauges may have the WB control unit built into the gauge, but I don't know for sure on the model you intend to use. The problem is that using the NB simulated signal from the WB control unit does not give the same voltage output to the LH than the stock NB (heated) sensor during the warm up period. That often causes a problem. That's why it is a better overall solution to keep the stock NB sensor all connected to the LH as it is, and add a complete WB unit and display separately.

 

Like I said before... I think I'm gonna stick my head under there and see how much space left I have for a second O2 sensor. Very informative posts here!

 

More cool info Thanks Jim.

I recently switched to using the ST2-supplied harness which gets voltage from the stock O2 sensor connector on the LH harness. The O2 sensor heater gets power from the fuel pump circuit, so it only comes on when the engine is turning.

What Jim describes is what I'm experiencing - using the narrow-band sim, the car always starts rich (around 12:1) and then works its way to stoic over about 20-30s.

In my old setup, the WBO2 was wired to switched voltage (via the diagnostic port), so was getting a few seconds of power to light off the sensor before the car was started (due to a quirk of the immobiliser), and I wasn't getting this issue.

Good to know another of the gremlins I'm seeing can be solved - I think I'll wire up a new power supply harness for my Techedge WBO2 controller using one of Ken's old LH-connector bridges to access pins on the LH harness so I can give it switched voltage again (and I'll also add wires to get rpm data and other stuff without plugging in the ST2). While using a separate NB sensor is ideal - if the car has stock cats with only a single bung, the NB-sim is the only option.

 

If it comes down to buying an Innovative or the AEM, the AEM is much better product. Innovative has some really bad heater control logic. They also require free air calibration. The AEM does not.

 

I agree, the AEM UEGO controller/gauge works very well and does not require free air calibration as 123quattro mentioned. We use AEM Electronics on all of our in house projects due to the reliability and as well accurate readings which we highly recommend them for our clients too.