Hello, a couple weeks ago I tried installing a Aem 03-0300 gauge into my 00 NB1. My problem was that the gauge would not read, it would warm up, read 12-15, then drop to "8.06". I had it set up to the cigarette lighter plug power and ground. I contacted aem to see if they would help me, they made me cut my sensor to send me a new one, but I purchased another brand new kit + a third bosch sensor on amazon. I tested both sensors, same thing, and put the new gauge in and the same thing still. I changed the ground and removed the inline fuse to see if maybe that would help, nothing still. I have two things that could be a factor, is it possible that the angle of the sensor could be bad? It sits directly straight down into the header on my ISR high rise headers.Could it also be possibl that it could from an exhaust leak on my headers? I can hear a slight exhaust leak that im sure is from the header to block connection due to a loose stud, but its not super severe, could that be it? If not, any insight will help tremendously, I would really appreciate it.

 

If it sets at 12 o'clock that's bad, 10 and 2 are preferred. Is the gauge for reference? Not controlling anything? Have you turned it on in free air for reference? I'm surprised they advise a different wiring setup.

 

Yeah, it's set directly at 12 o'clock with the wires going up and the 02 pointing down. The gauge is just there so I can get an accurate reading first, as it's not displaying anything in Tuner Studio either just the lowest "7". I have done the standard RCAL and nothing. Also did the free air calibration(removing it from the 02 bung, calibrate, reinstall), and nothing still, I've done it multiple times.

 

I'm assuming you mean 30-0300. I'm not sure about just the gauge, but when wiring the white wire 0-5v output, you need to also ground the brown wire, preferably to a sensor ground. Not sure if this is required for it to function as just a gauge.

I would check the voltage at the white wire, see if it's reading the same as the gauge, and at 8.06afr you should see near 0-0.5v. In free air it should be reading 4.5v.

 

Its not that its sending a bad signal, its that its not displaying any signal at all either. The brown and white wires are hooked up to a stock harness to the stock 02 sensor location.

 

I would try fixing that exhaust leak. IIRC my roommate's wideband was reading wild values after he rebuilt his engine due to some exhaust leaks. Certainly wouldn't hurt anything to get those cleaned up.