So I bought a RB streetable header for an FC for my gsl-se. Which works great. Except my stock O2 sensor seems to be a different thread pattern than the bung provided by RB.

I searched and it seems everyone says it's the same... but I promise it's not! I even bought a new bosch sensor to check if my threads were messed up and no dice.

I have read that the O2 sensor and bung should be 18mm 1.5 pitch. It looks like my GSL-SE unit is 18mm but has a wider thread pitch...

Any thoughts here? Will a second gen O2 sensor work if plugged into my GSL_SE computer? (I think second gens are wideband and SE is narrow band...)

I do not want to do the following things:

1. Buy a tap and dye kit/weld on a new bung.
2. "just run without the O2 sensor because it doesn't really do anything, man"

Oh and just to make sure I am not a complete dolt this is a picture of said bung.
This is the O2 sensor bung correct? It's not like an actuator port or something...

 

Every O2 sensor that I know of is M18X1.5. on my car I used a left over weld on bung from a motorcycle wideband sensor that I had laying around, the stock GSL-SE sensor fit just fine. You probably just have buggered up threads in the header, chase them with a tap and you will be fine.

Is the location of the bung in the picture the standard location that Racing Beat installs the sensor bung? If so it is a very poorly designed location, for one thing the GSL-SE sensor is an old one wire unheated sensor and having it that far down the header is probably not geed for sensor light off. The bigger issue is the fact that the sensor is horizontal, I design turbos and lots of manufacturers are starting to incorporate sensors before the turbine so I have to design the turbine housing to accommodate them. One of the most critical requirements is that the sensor has to be pointing up at least 10⁰, if the sensor is horizontal or pointing down it is possible to get moisture in the sensor from condensation which will destroy it.

 

Thanks MHR. Yeah I did some more searching and I believe you are right. Maybe just need to chase the threads in the header.

Also, yes, everything else you say also seems correct. My understanding is the O2 sensor isn't crucial for the SE. It will just run rich at low load. It is my racecar though so that may not be too much of an issue.

 

I never fooled around with unplugging the O2 sensor on my car, it has a sensor that is plugged in but it is probably the original sensor from 1984 so I have doubts if it is really doing anything for me. I have to pull my header and add a second bung so I can install wideband sensors for both rotors to work with my MS3Pro instillation, in theory I will be able to tune each rotor separately but I don't know how soon I will be able to get that part of the system going and if it will really give me any significant gains.

 

Here is what my car looks like now with the dual wideband sensors, should make tuning more interesting…