1JZ/O2 Sensor questions - can you secure it outside of exhaust?

[rob21a48422]

I have a quick question about my 1JZ and the stock O2 sensor. I have a '89 Turbo with a JZA70 1JZ swap about to be completed. I'm going single from the get-go and using a MAP-ECU2 for tuning. On the MAP-ECU forum most users say to leave the O2 sensor unplugged so that the stock ecu won't continually fight the MAP-ECU2. I'm afraid this will cause the car to go into "limp" mode and I don't want that. I'm thinking I might try leaving the O2 sensor plugged in but securing it in the engine bay outside of the exhaust. I'm thinking this may cause the engine to read "stoich" which will cause it not to try adding or subtracting fuel and make tuning easier. The only thing I'm worried about is whether the engine will think something is wrong when it's still "stoich" under boost. I don't know enough about open and closed loop I guess. That's where I'm hoping somebody can chime in. Any suggestions would be nice. I've tried searching but haven't come up with anything yet. I should also mention that I am using an AEM Uego to monitor AFR's and also hooking it up to the MAP-ECU2 for logging and tuning. Will this work?????

 

[rob21a48422]

Anybody???

 

[tissimo]

IIRC, the MAP ecu has a o2 voltage output (0-1v) that you can program or something similar. If that is the case then yea, you can leave the sensor hanging in the engine bay so it wont trip the heater circuit. If it does not have the o2 voltage output to the ECU then Itll read LEAN the whole time and the ecu will try to dump fuel to compensate.

 

[rob21a48422]

Yes, the MAP-ECU2 does have O2 adjust capability. I was hoping to not have to use it because I don't want to mess with cutting and splicing shielded wires. Oh well, it looks like I may have to. Everywhere I looked I couldn't find a definitive answer as to how to cut and splice shielded wires.

 

[Freshmaker]

I don't know much about the Map-ECU2, but leaving your O2 sensor open to the atmosphere will make it read off the charts lean.

Closed loop = cruise mode . it uses the O2 sensor feedback to reach a stoich mixture.
Open loop = hard accel mode. the O2 sensor feedback is both unreliable(narrow band) and to slow to use, so it uses a set map. "set" meaning the map wont change while under accel. The map may be modified by factors such as correction factor, air and water temp, enrichments and possibly other cool things i don't even know about

hope that helped a little!

 

[slideways2004]

I don't know much about the Map-ECU2, but leaving your O2 sensor open to the atmosphere will make it read off the charts lean.

Closed loop = cruise mode . it uses the O2 sensor feedback to reach a stoich mixture.
Open loop = hard accel mode. the O2 sensor feedback is both unreliable(narrow band) and to slow to use, so it uses a set map. "set" meaning the map wont change while under accel. The map may be modified by factors such as correction factor, air and water temp, enrichments and possibly other cool things i don't even know about

hope that helped a little!

this helps me. thanks! my car isn't street driven so i'm going to leave the stock o2 sensor unplugged for easier wiring and easier to build the downpipe (single)

my car will be tuned with mine's ecu+safc2. hopefully that will be good enough