This is my 5th Blazer/Jimmy and this is the first I've got that damnable secondary air pump on it. Now I'm familiar with the setup. I have one in the Trailblazer. Didn't realize they had these damn things in the Jimmy also. Anyway. As I've said before the P.O. did a LOT of work on this truck before selling it. But some of it was half-arsed. But one thing that was done was a completely new secondary air pump setup was installed. I guess the original was kissed. Anyway. I see the lines that come from the exhaust manifolds and hook up to the t-connector and the hose that goes to the pump. Now here is my issue. The hose that comes out. It comes outta the pump and up and over the radiator hose. First it was too close to the serpentine belt and the belt was starting to slice into the hose. Problem is, that hose....goes no where. So where if anywhere DOES that hose hook into. I get it that it brings warm air from the exhaust into the intake. But this hose is hooked up to nothing and I can not find anywhere where it DOES hook up. And worse I'm not finding any good images to show where this hose goes. So enlightenment will be appreciated. (yes I'm still searching for both/either)

 

OK. I found it. Guess it DOESN"T go anywhere. Just zip-ties to the fan shroud. What a stupid design. I wonder what it would take to remove that crap. I can see it was specifically installed on vehicles that went to certain areas. My Jimmy originally came from Maryland. I'm even willing to remove it, cap the manifolds and just live with the code.

 

The AIR system (Air Injection Reaction) system uses the pump under the radiator support to inject oxygen rich air into the exhaust system down stream of the exhaust valve to continue the combustion process burning unspent hydrocarbons in the process to clean up emissions and reduce fouling of the catalyst(s).

I believe the hose you are speaking of is the intake line that should be attached to the radiator support near the battery. The other hose will run to a 'T' at the front of the engine then off to two separate check valves (#9 & #13 in the image below) that make the connection between the hot side (exhaust) and the cold side (AIR pump) of AIR supply route. It is not uncommon for the check valves to fail resulting in hot exhaust gases moving towards the AIR pump in the system and damaging the rubber components along the way. Most typically the elbows (#16 & on the end of #8) get damaged and cause an exhaust leak in those areas. I have also seen where this condition can result in damage to a major wiring harness at the front of the engine if allowed to persist for a long period of time.


2001 AIR System Parts Diagram - courtesy of wholesalegmpartsonline.com

 

Yeah, that's the diagram I found (finally) Like I said. It looks like the P.O. replaced this entire system.