For those counting, the culprit was an intake manifold gasket which is being replaced now!

I have not had the opportunity to do the boost leak test. I don't have a garage or a place to even build the tester.I did order a tester and just got it.Wastegate tested fine.

Thanks! Will look into.A quick update: For the first time, I saw a CEL.I was on the freeway with the car and had to pass, WOT and max boost and it cut out, CEL came on.

I would agree 100%. I need to perform one still.

The car is 100% bone stock with 80k miles. Nicest DSM I've ever seen and I grew up in Ohio.I want to keep it all original and put it up for sale in a few months.ty!

My original BCS broke off a nipple. Figured no problem, I'll get another. Crazy, I can't find one anywhere. Discontinued across the board.Does anyone know how to find one? Mitsu parts sites say discontinued. One let me buy it, purchased it, and got a refund saying NOPE.Anyone have an extra...

Thanks for all the help guys.Had everything apart. Triple checked(with my mechanic) all vacuum.Did not do a vacuum test. It's Sunday and this mechanic starts his day at 7:45PM. May try but it seems less likely.In the process, we cleaned up the fuel filter(it was filthy). After putting...

Update: Ran the wastegate directly to the j pipe and it did the same thing.Also, in the process, a nipple broke off the BCS. So that's fun. Was pretty brittle but I also applied some unnecessary hand pressure.Looks like I'll be searching for a replacement

Also forgot to respond - that is mounted on top of the air canister and all connections look good.

It IS overboosting according to the stock gauge.Unfortunately the car is too clean and too original to install another gauge. It's probably the nicest DSM I've ever encountered. It looks brand new. I will definitely check those out, thank you.TY!

Thanks!I did double check that line and it's tight and uncracked all the way around as far as I can see without entirely removing it.Also unseated, cleaned and checked the MAF plug. It's pretty spotless. Wires are old but no corrosion and clearly pliable.This is super annoying.

Also, if it matters, it has 85k miles.

I appreciate both of your responses. Pardon my naivety here but would a clogged or fuel issue of any sort cause overboosting? It absolutely feels like it is. And it's a very mechanical, abrupt, consistent SLAM when it hits 4500 RPM. It's very on the nose, very repeatable, and almost painful when...

Hey all,As the thread title says, I have a 92 TSi that is completely stock outside of a cat-back and high-flow(but still restrictive CA legal) catMy mechanic removed the airbox to get to the radiator overflow tank to clean it off and inspect it. That's all fixed, everything back together...

Checked the shifter and all the bushings look mint. There's very little play in any direction. It's way cleaner, tighter, and better than I expected. Same with at the transmission. The left/right lever for the shifter moves up and down a slight bit but I would imagine not out of tolerance.I...