That little tiny plastic vacuum hose that's impossible to get at. It's probably leaking or off all together. The hose sticks out of the wiring harness in the back and is easy to miss. Take the rubber right angled connector off the manifold and stick it on the hose. Then when you put the manifold back on you can reach behind and slip the connector on to the manifold nipple. The nipple faces straight towards the passenger side. Trying to slip the vacuum hose into the connector with it attached to the manifold is almost impossible.

Thanks Andy. As you were probably posting this, I was out in the garage pulling it back off. When I was typing my post, a light bulb came on over my head! Wait a minute, where was the small hose in back that the install posts mentioned? I didn't even see it when I pulled the manifold off...the rubber elbow was still attached to the old one. You're right too about putting the connector on the hose first, then on the manifold nipple. Easy fix and now my air is blowing strong again.

BTW...time of first R and R....3 hours+. Time to pull it back off and put it on again right (at 10pm in a hot garage)....under 1 hour. Amazing what experience does!

That little tiny plastic vacuum hose that's impossible to get at. It's probably leaking or off all together. The hose sticks out of the wiring harness in the back and is easy to miss. Take the rubber right angled connector off the manifold and stick it on the hose. Then when you put the manifold back on you can reach behind and slip the connector on to the manifold nipple. The nipple faces straight towards the passenger side. Trying to slip the vacuum hose into the connector with it attached to the manifold is almost impossible.

Robert, Ever get your Shifter done? Have you had a chance to test it out?

Thanks Andy. As you were probably posting this, I was out in the garage pulling it back off. When I was typing my post, a light bulb came on over my head! Wait a minute, where was the small hose in back that the install posts mentioned? I didn't even see it when I pulled the manifold off...the rubber elbow was still attached to the old one. You're right too about putting the connector on the hose first, then on the manifold nipple. Easy fix and now my air is blowing strong again.

BTW...time of first R and R....3 hours+. Time to pull it back off and put it on again right (at 10pm in a hot garage)....under 1 hour. Amazing what experience does!

You'll know if this line is open if you run it for a day or two - you'll throw an emissions code (I think it was P1441?) and eventually the "check engine" light will come on. This happened initially with my install. BTW - I have done a succession of mods (most lately, Mallett ported LS6 heads and the 2002 LS6 cam, and these nowhere near the effect on performance compared to the original switch to stock 2001 LS6 parts. This is subjective; I have never had it dynoed.

Anybody with a 2001 (non Z06) that has gone to the 2002 LS6 intake? Is it worth it if you have not done the H/C on a 2001?


[Modified by direland67, 12:07 PM 6/11/2002]

How does the truck manifold compare to the LS6?

The LS6 manifold is a great mod! I just had one installed yesterday along with a set of longtube headers and there's quite a difference in how hard this thing pulls now above 3500 RPM. I realize my gains are probably a little more significant since my car is supercharged, but I can see where a stock LS1 would benefit from it too.