I have a 2006 Volvo s60 2.5T AWD and looking for some insight on a power loss issues I have. I am leaning towards a possible vacuum leak, but unsure. Symptoms: I pulled intermittent bad ground codes going to my fuel senders on both sides, fuel gauge stopped working or moved around, confirmed it to be within the unit and replaced the fuel pump and sending unit to fix that issue. The sending unit wasn't moving the gas from the left side of the tank to the right. Seems to idle okay and drive okay, but just does not have proper power and the boost is getting stuck at 4-5psi (added gauge coming right off the manifold.) I did a smoke test and got 0 leaks, filled the entire intake system and let it flow from the manifold to the air box. NOTE: I took my car to volvo a few months back for a software update to see if it would get the R headlights to work, but it didn't and ever since then my car was running at 12psi boost, but I haven't had any issues from that, just a reference for where the boost should be. I did add the HD TCV from IPD because I read that the stock one for my car wouldn't like that higher boost level and would probably die out prematurely. When I get home after work today I want to clean my air filter and swap the stock TCV back in and see if it makes any difference. I also had a spare MAF laying around so I swapped that in to see if any difference since I did pull a P0101 code that went away on its own the next day. This was a couple weeks before my power issues and didn't seem to make the car run any differently. I would get into my car with VIDA but my laptop is acting up at the moment so I had to use my Autel scanner

 

does anyone know if the brake vacuum pump is supposed to make noise when the key is on and when the brake pedal is pressed? I have a feeling the valve in the vacuum pump is bad because of the noise and if I pump the brakes and hold it compressed the pedal slowly drops and during my test drive after doing the fuel pump the brake pedal was often hard to press.