installed a trickflow street heat intake on my '92 5.0 a bit ago and im running into some vacuum leaks, i think. And it all became noticeable after ugrading this intake from stock... hesitation between gears, rough idle, spitting codes out and such, and i was wondering if anyone had a clear picture of where the vacuum lines underneath the upper intake go to? thanks!

 

where the vac lines actually go is irrelevant.

As long as ou have everything connected to vac that should be, you are all set. The problem with the TFS intake is sadly in its design. Most people cant get the rear most bolts to tighten down enough. Take the upper off, get some gasket tac spray, spray the gasket and lay it back in place. then make sure you tighten the bolts well.

 

Yeah, when I purchased my car, the previous owner had put two bolts through my TF intake manifold straight through it to keep it sealed (apparently he was having issues with it as well).

Just in case this is not your actual problem and you do have vacuum issues, here is a diagram of the vacuum lines:

http://www.veryuseful.com/mustang/te...g5.0Vacuum.gif

 

check egr valve, its the smog stuff on the left and side towards the back of the manifold, had the same problem, and it sounded just like a header leak

 

so i bought so carb cleaner and tested my engine out for leaks.... the egr gasket was leaking :/ bought a new one, applied rtv, and stuck it back on there. leak gone. but im not sure if im spitting out the same codes, as my CEL has burnt out again :/