08 dragon RG 700

Hello all, BD RG turbo, simple tuner ADA, EBC... Been chasing a boost leak, symptoms are that it engages at 4k, and has a heavy bog until it reaches 5200 then it'll pull your arms off. With any resistance from a stop it sputters for about 5 seconds before reaching enough boost to kick in, around 5200 rpm.
Put in new stock reeds, throttle body reinforcement, made sure airbox has good connection with the tb boot, same with airbox to intercooler. Replaced exhaust bellows, cleaned exhaust valves. Have yet to replace the fuel filter, probably desperately needs it.
Questions.... Where else should i be looking? Is it possible that my egt connections are suspect? friend tells me that i should be using a hi temp gasket style sealant on all my exhaust fittings, pipe, Y, opinions? Any other suspects on the boost leak list? Could a neglected fuel filter cause these symptoms? Any input would be much appreciated.

Going to do whatever it takes to run well this year, appreciate the input on what is obviously a tired subject here. Possibilities...will take a closer look at my Pipe, as you mentioned, will seal all exhaust connections with hi temp silicone, oil pump cable? Maybe its stretched or broken defaulting to full pump? Going to replace my tb boot for good measure... Fuel filter, going to attack it from all angles this weekend. Thanks for the input, will take it one step at a time and get to the bottom of it. Just need to find time to work on it! Thanks again

Center section hacked, massive boost leak, much better now, thanks for the input kestrel.