355 F355 subdued after Tubi manifold upgrades

warm the car up, stick on a suitable glove then have someone rev the car whilst you hold the valve open. Then you'll be able to hear the sound known the valve is open. Then do the same, have someone rev the car while you watch the valve and see if it's opening.

Go from there.

 

You can remove the hose from the bypass valve solenoid. Open valve by hand, finger on hose, making sure that hose holds vacuum.

Check that the vacuum canister itself is storing vacuum.

Make sure the electrical plugs for the bypass solenoid and air injection solenoid are not swapped.

 

Just telling you things that would take less time than even driving the car back to them but whatever you prefer.

 

Every time I've suspected my valve wasn't opening, it wasn't. Usually just a small thing and easily fixed - like a crack in the vacuum hose to the diaphragm.

"If there is any doubt, there is no doubt."

 

Sounds like to me there's something wrong with the way they put it back together.

The difference between factory headers and Tubi headers is not THAT discernible. I would wager your valve isn't opening.

 

on a 5.2 car aren't you suppose to get a CEL or something if the valve isn't opening?

 

All good no worries. Tape? Nevermind, drive it back to them

The "T" is connecting both the bypass solenoid and the air injection solenoid to the vacuum canister. (vacuum source for solenoids)

The top port on the solenoid closest to the cat ecu connects to the small hard line on the air injection tubes which then connects to the vacuum hose to the bypass valve.

Any hose that is cracked cut back to where it isn't and put it back on (or replace if brittle). The "T" doesn't look original and may be slightly too big causing the hoses to split.

 

That's probably as bad as trying to use tape.

 

It's your car to do what you like with of course but a hose inside a hose with tape and clamps is a literal dumpster fire.

Pretty easy to fix it correctly so you won't have to worry about it again.

 

121793 Ferrari

 

Yeah I don't know because when I have a hose that's so brittle it's splitting I just replace it.

 

Any 4mm vacuum hose will do. The O/D of that blue fitting looks quite large however.
Regardless, it seems like a vacuum leak maybe your initial culprit.
https://www.ebay.co.uk/itm/364222442994?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338590836&toolid=10044&loc_physical_ms=41774&customid=00ddb428eb021d8aa2ccdca9d2545d32&gclid=00ddb428eb021d8aa2ccdca9d2545d32

 

Vacuum (by nature) will be all or nothing.
That said, worth checking the operation of the valve itself (both for rattles and smooth opening).

 

At 10 psi, the valve fully opens. Anything from 0-10 psi results in partial opening.