Questions about Wideband sensor setup
 

Hello - I was hoping for some advice on the Wideband situation for my particular application:

1. Previous owner installed a FJO Enterprises Wideband Oxygen Sensor controller and Sensor 2 in. down from the converted single turbo around 20 years ago. From what I can tell, FJO was at some point acquired by Holley but I haven't found anyone at Holley who supports the product given its age. Some basic documentation I found is here - (http://97supraturbo.com/Manuals/FJO%20Manual.pdf and https://3000gt.com.au/car/Emanage/Wi...%20rev%20C.pdf) .

2. I recently bought a new AEM A/F gauge with it's own Wideband Sensor. The documentation states to install around 36 in. downstream from the turbo in this application. Thusly, there is now an O2 sensor port in my exhaust downstream around 36".

I'm trying to understanding if there will be any ramifications from removing the FJO system from anyone that may have experience with it's capabilities or, frankly, knows more about these types of systems than I do. It's clearly old and unsupported. It appears to me from the documentation that it is only reading values from the sensor and RPM with output to their proprietary gauges (which I don't own) or a computer (which I don't own the cables) and removal shouldn't impact the tune. I'm also considering how well the sensor can be working given how close it is to the turbo and my understanding w/r/t proximity and heat.

Thanks and happy Thanksgiving!

I would double-check if the Analog Output from the old FJO controller goes anywhere. If it had been connected to an aftermarket ECU configured for closed-loop operation, you might get unlucky and the ECU might do dumb fuel trims when the input wire is disconnected. If it were my car I might replace the old O2 sensor with a blockoff plug, but if it's not already leaking it might be fine to leave as-is.

It sounds like you've already added the new O2 sensor port, but be mindful of the AEM instructions that say to mount the sensor pointed down. It's good to avoid condensation (from the exhaust gases) collecting and pooling up inside the sensor.

Thank you, Scotty. I did observe the > 10 deg rule in the AEM documentation. I was, too, thinking of blocking off the existing o2 sensor port once I disconnected the old system but I'll check into what else is connected and report back!

You can always try the new O2 sensor in that location. Many will not like the extra heat and will error out - typically it will flat out give you an error code.

I always llke installing wide bands at the end of the downpipes before the flange for the cat/midpipe. Plenty of room for it there and the exhaust gas will be cooler by that point to keep the sensor from overheating.

Dale

Thanks Dale! I actually had the port drilled shortly past the flange on the midpipe to meet the requirements in the instructions, it was easier to remove, and there was a ton of room. Happy Thanksgiving!

Montego,

I did the same. Had the bung in the downpipe 6" away from turbo outlet and purchased the same AEM and had a bung placed in the midpipe right after the flange. Blocked the original with a bolt and one small tac weld to ensure it doesn't back out.

I think placement in the downpipe ensures the life of the O2 sensor, especially with our higher heat rotary applications.

Eric