After months of a couple psi of turbo loss, and a squeaking engine brake, loss of fuel mileage, I finally figure out it must be the epg. My fan clutch has been squeaking as well recently. Yesterday it was raining and I went to use my engine brake to slow down on an off ramp and it just sounded like air with water rushing through it. I then went to leave and I was down below 10 psi turbo and no acceleration at all. I guess this is my epg stuck closed? The psi would eventually return to around 18 psi and have some power but i used to get 30 and had been around 27 for a month. The epg parts are really expensive on this. Is it worth trying to clean it? I havent found any aftermarket at all. Epg 20722238 06 volvo d12. $1000, valve $600... if i block off the intake i just lose my level 1 exhaust brake? Apply air pressure to get it fully opened? Thats what ive gathered reading all these posts. Any help appreciated.