The air pipe to the pre-monolith converter broke loose. I'm reading from the FSM and it's the only thing I can find that looks similar. Do I need it? I'm guessing this is just more emmissions crap that I can live without.

I've been meaning to drop the cat and clean its innards out. I live in SC so I don't have to worry about a smog check.

 

I believe it is to add air (oxygen) to the chamber to after-burn the emissions, moreso.

 

And why can't it add air without the pipe? Unless you are running thru water, it will get air all by itself with just a hole.

Well, I guess it's 1/2 a pound lighter now!!

 

It is used to bring air into the cats at low RPM in an attempt to generate lower emissions levels at lower RPMs

 

But mr. bob, you want air injected only *sometimes*. Air at the wrong time can result in increased emissions, from too lean of an exhaust mixture going to the main cat.