Yea, plug the other. You don't need much pressure, like only 10 lbs, if that. A rag will work. If your tail's or tips are 2.5's, the Ridgid shop vac step reducer fits perfectly lol. But that's only if you flip it around and plug a 1/2 air line into it, regulated to about 20 lbs. But yea, just rags will work around any vac hose with vac in blower mode.

When I say document the leaks, it's because the smaller leaks will seal themselves at operating temp. You have to kinda weigh all that yourself or judge, but SOME will depending upon how small they are and where they're at. They may not seal at all at the convertors and @ Op temp because the converter flanges are of a different schedule.. - They're a lot thicker. More of a heat sink vs other joints.

Like I said, you'll notice the difference between a small and large leak when doing this.

Any leaks past the Y doesn't matter since efficiency monitoring discontinues after the downstream O2 sensor.

Fun fun fun...

 

I appreciate it Jim. I'll try to get to it this week and report back

 

No problem, -yea, post what you find if you get a chance.

 

Did I ? Was it any good ? A song lol. You recall the thread ? Huh, to many fumes in the shop that night I expect. I came up with a song for Jim Allen once. Don't recall much there either ,except, -he didn't appreciate it all that much and Patrick telling me I better go to bed lol. Oh well, heck with it.