Greetings,
I’ve recently installed the wideband sensor as a replacement for the stock narrowband on my 2002 MR2. It works great while driving, running smooth while cruising or full throttle. The issue im having is the sensor doesn’t seem to output correctly after startup.
For the first 10s after engine start (I have the sensor powered off the EFI relay so only on while running) it follows the low-high output behavior listed in the troubleshooting guide.
But for about 10s after that it stays frozen at a value of about 14.5 before suddenly jumping up and reading accurately (around 18 or so). The problem is the ECU has gone closed loop at this point and starts to stumble on the inaccurate reading. As soon as the AFR unfreezes and displays correctly the ECU compensates and everything is smooth again.
Is this something that can be configured, or is this just an inherent limitation of how quickly the sensor warmup? Thanks!
Heres a quick chart from my OBD reader. The whole time the sensor is “frozen” the short term fuel trim is being dragged down, and as soon as it unfreezes the trim starts to recover and the engine idles correctly again.
The wideband is designed to output 1 Lambda until the sensor is at operating temperature.
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Thank you for the reply. I’ve been logging voltages on the different pins, and Im seeing odd behavior on the narrowband emulator. The wideband pin properly outputs lambda = 1 during warmup, but the narrowband pin also outputs 2.3V? If this was the 5V output that would be correct, but the proper narrowband lambda = 1 should be 0.45V right?
It’s only during the warmup cycle. As soon as the sensor starts reporting, the narrowband returns to correct range. Is this a bug on the firmware version I’m on? Thanks.
Yeah, with gauge disconnected, powering on the device has the following behavior:
First 5 seconds:
High perf output=1.67V
Std output=0.47V
5-10s:
HPO=3.34V
STD=0.47V
10s+ (until sensor warmed):
HPO=2.35V
STD=2.33V
I flashed the Spartan back to version 1.08 and it doesn’t do this. It stays at 0.47V throughout the entire warmup.
That is odd, I will look into it, thank you for bringing it to my attention.
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