[RotarySwingGolf]

Decided after owning my car for four days I needed a Capristo exhaust instead of the Tubi that came with it. The cats were failing so I ditched those for some custom straight pipes at the same time. After putting on the Capristo and driving for the first time I was devastated by how weak it sounded at higher rev's and figured the bypass valve wasn't working as that seems typical even though mechanically it was working fine when I removed it and cleaned it. I saw that the very end of the hose that runs to it was slightly frayed and nipped the end off, not really thinking it would fix the problem, but it actually did and now there is so much vacuum that the thing stays open the entire time, even after turning the car off! While it sounds great, I don't want to run it open like this all the time and would like to figure out the vacuum issue as it seems I'm the only one on the forums that has had this problem instead of it being stuck closed.

Any ideas? '98 355

[ALEX A]

You should not have vacuum at idle to the valve. make sure that no one crossed the vacuum hoses. Very possible that the valve is no good. You also can remove the valve but have to program the computer. The car would sound amazing. I have done a fews cars for my clients . They were very happy.
Alex.

[RotarySwingGolf]

Originally Posted by ALEX A

You should not have vacuum at idle to the valve. make sure that no one crossed the vacuum hoses. Very possible that the valve is no good. You also can remove the valve but have to program the computer. The car would sound amazing. I have done a fews cars for my clients . They were very happy.
Alex.

I have a Capristo exhaust and my understanding is that there is less of backsliding problem with this exhaust compared to OEM when removing the bypass valve and driving at low rpm's, so that is a possibility, but I'd prefer to get it working. The valve is working fine. When I start the car it is closed, but revving in neutral it opens up at around 3-4k rpms and then stays open for an hour or more after I turn the car off, so I'm wondering if it's the bypass solenoid. It's clearly creating plenty of vacuum, but then never releases.