Hey Yall,
Need some help with my 2001 VW Golf GTI 1.8T... I know alot about cars but never had a turbo engined before this.. so certainly new to *** Would it be worth it to put a BOV on this car with a cold air intake with a full cat-back exhaust... With regards to the intake will it mess with the MASS air flow sensor? Where some suggestions to buy the stuff for a decent price?? Where to find some instructions on installing these parts myself?? Thanks alot for any help I appreciate it.......
Thanks JOSH  

The 1.8ts tend to work best if you stick with a diverter valve similar to the one that it cam equiped with from the factory. You can upgrade to a rebuildable piston type instead of the diaphram type, but I would stay away from BOVs.
You didn't mention that you had done a chip on the car. This will give you the biggest increase in performance, especially for the money. If you really want results from the exhaust you will need to do a downpipe along with the cat-back system. For the chip, APR, GIAC and Neuspeed all have a good program. For the exhaust, again several companies make good exhausts. As far as I know, autotech is one of the few companies selling an emissions legal downpipe.
When it comes to the intake, several companies make good intakes, and to be honest they are all really similar. To see bigger gains you will also want the turbo inlet. ABD, Neuspeed and Forge all make good pieces.

Hope that helped, post up any other questions you have