Figured I'd give an update to the thread. After several tuning changes and noticed the egt were climbing higher each time I drove, I decided to do a boost leak test and found a massive leak at the Y bridge. Wasn't too thrilled as it required me to pull the valley turbo and found oil in the compressor side. Had the turbo sent out to be inspected and I did hurt it.
Upon repairing the y bridge leak, I discovered that the factory seal whether it's a GM or Mahle seal, the seal compound not hard enough to hold the pressure in, even with 4 lower studs and torqued to 100 in-lb. After 30 psi, it would push the seal out in the seal alignment channel and cause a significant leak. That caused to erode the seal each time it leaked and got worse over time. I used anaerobic sealant on the inside next to the seal to correct the issue.
That's all fixed now and it's running much better, however having stock high mileage injectors in, I finally popped the P0087 code on a hard WOT run which is a clear indicator for high return rates. Time to save up for injectors but at least it's good enough to tow my camper, overdue for a family camping trip. Just need to do some simple MAF changes and lower the fuel pressure due to having a hard time holding speed between 75-80 mph, too sensitive on the throttle.
