Brake booster check valve

[ThePresidential]

I need to replace my brake booster check valve because it’s leaking. The check valve has a hose going to the brake booster, a hose to the vacuum source, and another hose connecting to the intake pipe.

My question is when i replace the valve can i just connect it to vacuum? Or do i need a 3 port one that connects to the air intake? What is the need to have it connected to the air intake?

[ridered74]

Need is a really strong word....not sure why they have it going there, but I know a bunch of people plugged that part of it a couple years ago when a lot of people were noticing hissing sounds from that connector. Never heard of any ill effects from it, so I'd say you should be fine removing that connection.

[Macgyver]

My SHO had that part that hissed. I left it alone.

[ThePresidential]

Need is a really strong word....not sure why they have it going there, but I know a bunch of people plugged that part of it a couple years ago when a lot of people were noticing hissing sounds from that connector. Never heard of any ill effects from it, so I'd say you should be fine removing that connection.

Yes i dont need it, its not throwing any codes. But its a small vacuum leak and i dont like to hear a leaking air sound. And i would like to see my ling term fuel trims as close to 0 as possible.

[ridered74]

Need is a really strong word....not sure why they have it going there, but I know a bunch of people plugged that part of it a couple years ago when a lot of people were noticing hissing sounds from that connector. Never heard of any ill effects from it, so I'd say you should be fine removing that connection.

Yes i dont need it, its not throwing any codes. But its a small vacuum leak and i dont like to hear a leaking air sound. And i would like to see my ling term fuel trims as close to 0 as possible.

My long term trims were 1.14-1.18 the entire time I owned my car. If they're still off after you fix that hissing sound, good chance it is your fuel pressure sensor. Those seem to go bad pretty often and cause the fuel trims to be off.

[ThePresidential]

Right now mine got down to 3.1 and 3.9, would bad cats affect your LTFT? Im waiting so i can get downpipes to replace mine.