Barrett 98z28

Just bought a mpvi2 from hp tuners. Hooked my wideband and into my bank 1 O2 bung and datalogged the car. It was reading extremely rich all the time, high 10’s or low 11s occasionally. Was going to adjust the tune, but decided I better confirm my wideband was working correctly, so a couple days later I hooked the wideband up to see what it registered with the engine off and it was still reading around 10. It should be reading maxed out lean shouldn’t it? I have the two black wires connected to each other and the blue input wire from the mpvi2 going to the white wire on the wideband which is supposed to be the analog input wire. I could wiggle the black wire(which is ground I believe) and the reading would lean out to around 15, but still when I start the car it would then stay around 15 not changing. I’m running a wideband off of a aem 30-4110

ChopperDoc

Sounds like you have a ground wire issue. I know on the MPVI 1 that the black wire (ground) went to position 5 on the unit, and the input could be put on pins 1-4 (new on has positions 1 and 2). I don't see why the new one would be different. Should be a ground wire on the unit. The one from the gauge (analog out) should have 2 wires. Ground and signal. Then you should have the gauge/sensor grounded to the car as well, since it has it's own ground. The only time you have to tie the grounds together normally is when the readings don't match the scanner and gauge.

I'm not cool and don't have the new unit yet, but I would definitely research which pin on the MPVI2 is the ground.

Barrett 98z28

i didn’t even buy a gauge, I just bought the sensor alone. I thought the sensor would ground out on the exhaust, but do you think maybe I should run to a good chassis ground and then see what it does?

ChopperDoc

Yes the sensor needs to be grounded. However I will say, if it does work, you won't be able to verify the number it gives you. Perhaps if it close to the stock O2's, but even then, still kind of defeats the point of having a wideband. The gauge will tell you exactly what the number is, and also provide an analog output signal for use with your HPT unit.

Widebands aren't so expensive that I would be taking the risk of it giving you faulty numbers, personally. I have several of them now, all AEM's. They seem to work pretty well, with gauge and they are also supported by HPT in the scanner, so transforming the signal is easy.

Did the sensor come with a transform formula by chance? It will tell you what each voltage represents from the signal.

Honestly you'd be far better off just getting a full WB kit, with gauge. Another thing you can do is buy a 12v adapter and wire your power and ground to that for the gauge. Then the outputs to the scanner, and of course the sensor itself. I have a setup just like that I use for tuning, all wires neatly wrapped. Very cool to have a portable WB. I only say this as it sounds as if you do not want to permanately install it in your car perhaps. That's a pretty sweet alternative which you can just unplug and take out of the car.

Barrett 98z28

yes the reason I only bought the sensor was because I didn’t want a permanent wideband. From what I researched, I thought you could go off the analog input wire, and the hp tuners software had where I could select what sensor I was using from a preloaded list. The sensor I have was in the preloaded list, but since I’ve been having this trouble I read more into it and more people are doin like what you said, and using the output off of the gauge. I like the setup you mentioned of having the 12v power adapter, I’m gonna give that a try, and go ahead and buy a gauge. Thanks for all the info