I'm planning to Install the invidia o2 housing and wondering if I buy I new oem gasket, will it fit the invidia housing?

 

it comes with a gasket for the down pipe, and I reused the gasket to the hot side of the turbo and had no leaks because it's super thick

 

Be certain that you have the Invidia down pipe gasket before you take things apart. Its made of brass, and the oem Mitsu gasket will not fit. I ordered a spare for mine, and it took about six weeks to get it.

You probably know that the Invidia housing relocates the O2 sensor in such a way that the sensor wires will no longer reach. Invidia recommends soldering an "extension harness" between the O2 connector and the sensor. Some owners have done that, but I don't like the idea. If you want, you can unplug the O2 connector under the coil cover, and remove the connector wires from the plastic harness protector to a point about level with the bottom of the throttle body inlet. This will allow you to run the O2 wires around the opposite (driver's) side of the motor. You will have more than enough length to reach the relocated O2 sensor, and no messy soldering, etc. Finish the job up by re-taping the plastic harness protector, and run the exposed O2 sensor wires through a length of new split plastic harness protector. I think I used 1/4 inch ID, but I'm not certain. Hope this helps.