Need downstream O2 sensor ASAP!
 

So... I'm putting in a P&L header, and things are going well until I try to take the downstream o2 sensor out of the factory manifold. Talk about tight!!! I get it out and the the threads are completely stripped. I don't think it could even be re-cut to make it work. :sigh:

I go to Subaru, three parts dealers and check online....no quick fix. This part is not in the USA and no one could tell me if there was something 'close' that might work. A 4-day wait is the best I could do for the part.

I put one on order, but was wondering if anyone might have an idea about possibilities in the meantime?

If you need something to block the hole temporarily... a spark plug should work and you might have one laying around.
Oil drain plugs work good as well, but that will require a trip to the auto parts store.

I am going to replace my downstream sensor with a wideband, so I would be willing to sell... however, it is still installed on the car and I won't get to replacing it for another week or so.

Blocking the hole would throw a cel, but would this be a big problem other than a light on the dash?

Nope. If you disconnect the secondary O2 sensor and block the bung, you will get a check engine light for no secondary O2 sensor, and your cruise control will not work until you install a new O2 sensor and clear the DTC code.

Do you have unichip installed? If you have ecutek you can disable the check engine lights for the missing downstream sensor... not sure if you can do that with the unichip.

Either way, temporarily blocking the bung and removing the O2 sensor will only throw a code and disable cruise control. I've seen posts on forums that say removing the sensor will cause some strange air/fuel corrections by the ECU.... but I did not really notice anything different when I was running without a downstream sensor. On subaru forums for the WRX etc. people say they notice a slightly richer idle (14.4 vs 14.7), but not sure if this is true with this platform.

You should be fine until you get another o2 sensor or work out disabling the DTC codes with your tuner.

Thanks DJ!

Urgent
 

Hi I was wondering why I have the engine light on since I only have a catback. Q300. It just came on two month after installation.
My friend said it's the secondary sensor but the sensors are only in the header right? And if it was the installation shouldn't it come on sooner instead of 2month?
Thank you very much for reading:respekt:

O2 sensor removal tool helps

Catbacks without tunes can throw CELs occasionally.

I actually have it tune. but not custom tune. I bought the Perrin stage 1 stock tune and the tuner informed me that he can turn it off but the problem would still be there. In addition, he said that catback doesnt really require special tune. : / Let me know if anyone encounter this and how did they fix it. :sigh:

Thank you!