I'm not an engine guy, but want to learn. As part of the process, I'm trying to locate various parts on my 1989 Trans Am 5.7L TPI engine.

There is one item that is driving me nuts and hope you all can help identify.

If I'm looking at the car (facing the front winshield), there's a rusty looking pipe/tube on my right. Looks like it is below and just outside the fuel rails and has thin stainless tubes coming out if it.

I don't know if this is an emissions piece or not.

 

Sounds like the air injection tube. It routes air from the air pump (smog pump)to the exhaust manifold, and injects air at each of the four exhaust ports. If you look closely you'll see that there's one on each side of the engine.

 

Thanks.

Next question. How hard is it to replace these, if I want to dress up the engine.

 

Not difficult to replace, except if the air valve threads are really tight. It's the black thing that screws onto the inlet side of each air tube. You'll probably want to replace them too, they're cheap.

 

mnorton:

Thanks for the info. Searched some threads about the AIR system and see where some folks have removed theirs altogether. Hard to do? Would I want to?

My situation is this, I purchased my '89 TA from a neighbor who had the cats cut out, presumably for more ponies. However, he left the AIR system in place. I read on another post where if you have that situation, you get a nice "popping" sound from the exhaust system. I have this, especially when deccelerating and letting off of the gas.

So, should I have the exhaust redone and put in some high flow cats to re-engage the AIR system, or should I just pull the AIR system?

 

There's so little power gain in removing the smog stuff that I think it's best to leave it there. High flow cats work so well that there's no reason not to have them. Catco cats are a good brand, Summit sells them. Plus it's good for the air, global warming and all that......

 

If the cats are already gone though, the AIR system isn't doing much useful.

 

Would this be the check valve or the diverter valve?

Diverter valve is $300+

Check vave is about $20.