A few months ago I got my WRX road tuned by IA Performance and we had it peaking at about 16.5 psi. I swapped in the GS EBCS just before the tune and on the first WOT run I was only hitting 10 pounds. He had me double check that the EBCS was hooked up correctly and I triple checked that it was. He had me tighten up the wastegate actuator arm a bit and that still didn't help achieve higher boost levels. So he cranked up the wastegate duty cycle to around 90% which had me a bit worried. But being that I am pretty new to turbo cars and know nothing about tuning, I asked him and he reassured me that it would be fine. I've noticed over the last few months that I'm hitting lower and lower peak boost levels at WOT and now I'm maxing it at about 12-13 pounds.
Is running the wastegate at 90% duty cycle wearing it out and making the wastegate door open sooner or wider or something and dropping my boost levels? Does this IA Performance guy have no idea what he's doing or what? And if the wastegate is bad, can I replace it or fix it?
/Long story bro.