Bogging down under high boost

[Mister Anderson]

My 91 Legacy turbo seems to be bogging down under high boost 8+ psi. When I turn my AEM Tru boost off to stock waste gate pressure it seems to be fine (6psi but still stumbles). Before it started to bog down the engine would seem to stumble under full boost at WOT or 4th gear (4EAT). My boost is reading all over the place, 6,8,13,11 ect ect never constant with the gauge on 12 psi. The car would stumble before I added the boost controller. The BOV sounds like it's wide open when it starts to bog down. The last couple weeks the car would randomly die at low speeds 5 MPH or so. It has the OG fuel pump so maybe the fuel pump is on its way out?

P.S I have tried 3 different turbos and all the same out come.

Stock WRX BOV and intercooler
TD04-13t
Delta 230 regrinds
AEM Tru Boost.

[Legacy777]

I'm sure the Delta 230 grind cams are probably not helping the idle and could be a contributing factor of dieing at low speeds.

What troubleshooting have done so far? I don't think the issue is the turbo itself, but possibly something with the vacuum/boost lines, and BPV.

[Mister Anderson]

I'm sure the Delta 230 grind cams are probably not helping the idle and could be a contributing factor of dieing at low speeds.

What troubleshooting have done so far? I don't think the issue is the turbo itself, but possibly something with the vacuum/boost lines, and BPV.

Yeah the 230's give it a nasty idle. Everything has been great up until this week or so. gauge is reading around -9.xx at 60 mph on the freeway. The BOV is hooked up to the manifold where the stock SS was. I installed that long ago with no problems. I have checked and recheck all the vac lines and boost lines. Throttle is good. The engine is not throwing a CEL.

[Mister Anderson]

The custom fabed y-pipe I made is toast. That's probably the problem.

[Mister Anderson]

Put a full silicone Y-pipe on and it fixed the problem!

[Legacy777]

Good deal...based on your comments about the AFR being around 9, I would have expected there to be a leak somewhere like you found.

[Mister Anderson]

I knew that Y-pipe I made would have to be replaced at some point. I was just being cheap lol. Now if only the transmission would be nice to me.......