AE101 4AGZE Air fuel ratio gauge

[Steven T]

I have spliced the signal wire from my afr gauge into the black and white wire from the ECU

Is this right?

It's just that when I turn the ignition to ACC the gauge lights up fully rich, then when I start the car the ratio goes from stoich to lean and then off the dial, it takes maybe twenty seconds for it to go completely off the dial. Whenever there's more than maybe 50% throttle it goes all the way to the right., fully rich

Is it the car, wiring or gauge?

Cheers

[Kiwi-Corolla]

Welcome to the forums! I've never installed an air/fuel ratio gauge before, but I had a search for some 4A-GZE ECU pinouts online and the black and white wire that you spliced into definitely seems correct. Perhaps you need to upgrade to a wideband o2 sensor for it to work. Might be worth getting some free advice over the phone from an auto electrician tomorrow. Good luck!

[Hiro Protagonist]

Using the factory lambda/O2 sensor for an AFR gauge will give you bling and nothing else - they use a narrowband sensor and thus only have three levels - lean, stoich, and rich, so all you'll get is a needle flicking wildly from left to right showing nothing useful.

As Kiwi said, if you really want a proper AFR readout then you'll need a wideband sensor.

[speedy25]

The only time you can get a real reading is at WOT.

-SP

[Steven T]

So there's no need to get alarmed?

And it should work on a wideband sensor?

Also what is WOT?

[Kiwi-Corolla]

Originally Posted by Steven T

So there's no need to get alarmed?

And it should work on a wideband sensor?

Also what is WOT?

Yeah it should work if you get a wideband sensor. WOT = wide open throttle.