home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > performance & modifications

Reply
 
Thread Tools Display Modes
Old 08-19-2020, 02:39 AM   #1
StreetForged
Board Member
 
Join Date: May 2018
Default Changing o2 Sensor Location

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?
__________________
StreetForged is offline   Reply With Quote
Old 08-19-2020, 02:55 AM   #2
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

Quote:
Originally Posted by StreetForged View Post
... only has 1 o2 sensor precat.
Post cat sensors are only on modern cars. They are there to measure catalyst efficiency.
__________________
No Start Thread
ZVOLV is offline   Reply With Quote
Old 08-19-2020, 03:16 PM   #3
bobxyz
Board Member
 
bobxyz's Avatar
 
Join Date: Aug 2014
Location: Boulder CO
Default

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.
bobxyz is offline   Reply With Quote
Old 08-19-2020, 04:07 PM   #4
StreetForged
Board Member
 
Join Date: May 2018
Default

Quote:
Originally Posted by bobxyz View Post
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.
StreetForged is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 06:21 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.