• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Changing o2 Sensor Location

StreetForged

Member
Joined
May 24, 2018
I don't understand all the finest details of the functioning of sensors and the like, so I'm not sure if this is an issue. I am swapping exhausts on my 1990 240 to a 1985 240 exhaust that looks like its possibly had some custom work done. It has the cat deleted and each exhaust only has 1 o2 sensor precat. Neither exhausts had cats to clarify.

The part that concerns me is that the exhaust from the 85 has the o2 sensor right on the manifold, where my current exhaust has the sensor located in front of the cats old location. Will there be any change in the way the sensor reads that could alter the way the vehicle runs? My old exhaust is covered in leaks and rusty and this one is in immaculate shape. I could move the o2 sensor if I absolutely had to, but I'm assuming any difference would be negligible?
 
The O2 sensors only start working once they're heated up. The early ones used a single wire narrow band O2 sensor very close to the engine. These heated up quickly.

The later ones went to a 3-wire sensor, with the other 2 wires being a battery powered heater. These can be located way away from the engine. Using a 3-wire sensor close to the engine is OK too.

If you ever want to change to a wideband O2 sensor, you should install a bung 18"? [check the WB02 instructions], or further, away from the engine -- the WB02 sensors don't do well with lots of engine heat (they include their own heater). The bung should be positioned so that if water/condensation is in the exahust at startup, that it won't flow into the O2 sensor.
 
The O2 sensors only start working once they're heated up. The early ones used a single wire narrow band O2 sensor very close to the engine. These heated up quickly.

The later ones went to a 3-wire sensor, with the other 2 wires being a battery powered heater. These can be located way away from the engine. Using a 3-wire sensor close to the engine is OK too.

If you ever want to change to a wideband O2 sensor, you should install a bung 18"? [check the WB02 instructions], or further, away from the engine -- the WB02 sensors don't do well with lots of engine heat (they include their own heater). The bung should be positioned so that if water/condensation is in the exahust at startup, that it won't flow into the O2 sensor.

I appreciate the info, the connectors are the same between these two sensors as well so I'm sure everything should be straightforward and turn out well.
 
Back
Top