Hi everyone!

Hoping someone may have some insight into to my issue...

I purchased my 2008 997 Turbo with the AMS Alpha 9 turbo kit already installed with roughly 28k on the odo about a year ago. The car ran very strong, but had an odd hesitation and would spike power on the dyno. I took it to a reputable tuner in my area who said I needed a Cobb AP in order for him to tune it, which I did purchased (the car did not come with the original). A couple weeks later, I got the car back and he said everything was good and that it's running about 24psi. (I asked for a safe tune/boost because I intend to daily this car, not race it)

As soon as I left and entered the highway, I got the car into boost and it immediately cut power and would only boost to 5psi. It was still acting strange, and so the tuner asked me to send him the logs from the AP. I did several runs and sent him 3-4 logs over the course of a few weeks. He would respond with a revised tune, but nothing was fixing my issue. Keep in mind, the car ran fine until you go it to about 23psi and it would go into limp mode. The tuner suggested my PBC Pro EBC was to blame and that the Tial ball bearing turbos needed to be replaced with stock VGTs. He recommended I replaced those or I would always have issues. I was skeptical because I've seen many 997s running ball bearing turbos with ebcs and no issues.

About a month goes by and I still have no resolution, but then driving around town I threw a P0021. I took the car to a reputable shop who diagnosed it with a spun cam sleeve. During this time I've not been in touch with the tuner. The shop has the car for quite a while and we did a lot of "while you are in there" services as well. Both Tial turbos were also rebuilt during this time due to excessive play in the impeller shaft (forwards and backwards play?). The shop owner said the spun cam sleeve could have been causing my limp mode issues, but we weren't sure. He also did not have any experience with the PBC Pro, so no changes were made. Prior to rebuilding the turbos, I called several turbo manufacturers and tuners asking for their suggestions (ball bearing vs VGT) and they all recommended I keep the Alpha 9s.

I finally get my car back, and it's running great, however once it goes into boost, it cuts power and will limit the turbos to 5psi.

Since it's a boost issue, and not the car limiting the throttle is this a simple setting in the PBC pro that is limiting the boost once it hits a certain point? The tuner swears it's not the Cobb tune, and I have no reason not to believe him however he's also not taking very much time to try and set the PBC. I'm a bit at a loss here and any insight would be a great help.

Thanks!