Hi guys,

im currently in the process of upgrading my exhaust and im planning on doing an ECU change in the not to distant future but that is not relevant at the moment and i don't want to start a flash vs aftermarket ecu debate.

What i want to know, the factory ct9a setup uses 2 o2 sensors. im planning on doing away with the sensor that comes off the dump pipe when i change ecu but for the time being is there a way i can turn off this front sensor and remove it using ECU flash?

i've had a quick play with ECU flash and my current ROM and i could not find any identifier that related to the o2 sensors and being able to turn them 'off'.

the rom im currently using is 96260007.

is it just a matter of disconnecting the dump o2 and having a CEL light until i change ecu?

Thanks

 

You must force the car into constant open loop by changing the open loop load to all 0's.

Then you must disable the heater circuit cell with a patch and probably need to use the force odbii success patch. Both which aren't defined for your rom as of yet. It would be easier for you to just use a rom which these are defined.

 

If it's a JDM car and you are using 96260007 you should only have one O2 sensor for closed loop control located in the turbo elbow, no rear.
To remove the CEL for the sensor, change the periphery at FAA to 0x5698, need to check what it needs to be for heater circuit CEL, can't remember off the top of my head.
As Roadspike said you will need to force it into openloop also, as it will run like crap if you just disconnect the O2 sensor and MPG will be terrible.
I can post an xml for 96260007 with open/closed loop threshold and the periphery defined when I return home, or you can just swap to the Tephra version of 96260009 if you can't wait, as it's just a newer version of 96260007 and the xml should have everything you need defined already.

 

so it turns out i've only got the single o2 sensor after all, the one that plugs into the dump pipe.

because i've only got to run a short distance without the sensor, how do the ecu's run without an o2 plugged in at all? do they just shoot out a cel warning and as a fail safe run richer?

 

It will run rich with no O2 feedback for closed loop, and yes you will get a CEL if disconnected.