Okay I am starting to install my XTC Downpipe right now, and just realized, the XTC only has 1 02 bung, and my car has 2 sensors going into the DP.

What did you guys do about the sensor closer to the exhaust manifold?

I have an 07 LS.

Okay, I figured it out guys. For 07, they used a different stock downpipe (I think). There are still two 02 sensors, but there are 3 bungs. Two in the stock DP, one before the cat and one after, and one in the exhaust manifold. They just threw a plug in the manifold bung.

I'll have it finished after a little bit, and post some pics. I might just make a how-to on it. Even though it is real straight forward, but it'll save some time for you guys looking for the right wrench. It might be a few hours, cause I'm chillin and drinkin at the same time. Guiness in the afternoon FTMFW!! Loosen one bolt, drink a beer, loosen another bolt, drink another beer.

 

What I was going to say but didn't want to look like a dork... I thought the first o2 sensor went into a bung (hah I said bung) in the exhaust manifold. I wonder why GM moved it further down to the DP?