I think this is the hose you are looking for:
https://www.rockauto.com/catalog/moreinfo.php?pk=6674740&cc=1424281&jnid=547&jpid=0
ACDELCO 15240704
After looking that the service procedure myself, they do say to remove the intake manifold. Just to get to the bolts I guess or to pull the part out? That plastic is not flexible on this Secondary Air Injection Pump Hose.
I do not know why they designed it like this, they have the AC lines ran all over the engine blocking things but they had to design a custom plastic baffel to wedge this behind the engine?
If you take that intake manifold off, make sure to replace the gasket and torque correctly. (ACDELCO 89017871) One of the bolts at the firewall is very hard to get to and torque, I HAD to use a swivel and compensated when I did. I had to hold the socket and swivel while someone else used the torque wrench. I am at 170k and my gasket was just destroyed. It was completely flat, I do not know how/why. (old, over torqued?)
You are also dealing with the PCM there which all the wires run to and the connectors/holders that hold those in. It is a bit of a mess. But it is manageable.
I used a Lisle 37000 Air Conditioning/Fuel Line Disconnect Tool Set (
http://www.amazon.com/gp/product/B0002SRCK6/?tag=gmtnation-20) to disconnect the two fuel lines. One was kind of a pain but you have have to take your time and work it a bit.
I also relieved the pressure like the manual says way before that (beginning of the job). You have to disconnect them because they are attached to the bracket that you have to unbolt. I ended up taking the "wire harness bracket" off/out completely because I was having problems positioning stuff out of the way. I used lots of zip ties to hold everything. I never took the wires off of the PCM (the procedure does not say to either).
At one point you have to 'remove' the crankcase ventilation hose (
http://www.amazon.com/gp/product/B00S0G05CE/?tag=gmtnation-20) to get to some bolts on the intake manifold. It goes from the manifold to manifold. I think I almost cracked my manifold getting that thing off. I did not remove it completely, just the top part. I wedged against the top of it. I did not want to twist as I did not want to crack the plastic.
Make sure to count the number of bolts on the manifold. Once you take it off you see how they are patterned but even then if I did not count I would have missed one.
I am at 170k and that tube was/is fine. I cracked just the top of this rubber vacuum line just a bit. I am going to replace. Next time I might take the bottom off first but the bottom has a metal clamp on it that you need to squeeze. I did not do that because I figured it might be hard to get to. I might do that part first. Or possibly I will just cut it off (without damaging the intake manifold) next time and expect to replace. I just did not want to crack the manifold taking this one tube off.
When I put the intake manifold back on I made dam sure that the gasket was still in the right position. The gasket fits into slots on the manifold, so it was not hard but I was able to double check with a flashlight.
I do not know how long fuel injectors last (
http://auto.howstuffworks.com/under-the-hood/car-part-longevity/fuel-injectors-last.htm) in a vehicle and I guess it is not a huge pain to take the manifold off (just some time) but I replaced my injectors. It was one of the reasons I took the manifold off in the first place (I was having huge issues with my vehicle) so this is a completely different situation. @ 86k you may just want to leave things alone but you will have access to your fuel rail and injectors while you have the intake off.
I do not know what kind of tools you have but when I did this on my
2004, I needed to torque the intake manifold bolts to 89 INCH pounds. Just to give you an idea of the type of torque wrench you will need. Let me know if you need procedures but it sounds like you have them already.