It's an o2 sensor non-fouler, used to space the o2 sensor out from the housing to prevent it throwing a code. I ran these when my cats went bad until i could upgrade to ART pipes (which have non-foulers built in). Unfortunately it kinda looks like the weld for the o2 bung broke off, so you'll need to have a new bung welded on, or get new cats/test pipes.

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It depends on what it came off (cats or test pipe), but they can probably weld it back on while it's still installed on the car. If not, getting the upper bolts for the catalytic converter is a bit of a pain, but the whole thing shouldn't take a shop more than an hour or two.

It depends on what code it was throwing.I don't remember the exact numbers, but if it's the code saying the cat is bad, then the non-fouler should take care of it. If it's the code that says the o2 sensor is bad ('low voltage' is in the code description) then it is likely a bad o2 sensor, which will need to be replaced. Your shop should be able to scan the codes and let you know, at most you're looking at $100 for a new set of sensors, and whatever the labor is to do the welding.

 

 

 

TBH I haven't had an o2 sensor go bad since my first little daily Civic back in college, and I think I just ran with the CEL on after that haha. I'd recommend Bosch just because they are a very reputable brand, but I believe they command a pretty high price as well. If you're planning on reinstalling a set of non-foulers, you probably can't go wrong with any of the brands since they won't be directly in the stream of exhaust. Good luck!

 

it's called a welding fail