Roush stock boost for an S281

[type R]

quick question got friend concerned about his car...he says he's only seeing 4 p.s.i. has hi flow cats ,K&N and exhaust? is this with in normal parameters or low?

 

[RED92VERT]

4psi seems low, I would get a new boost guage and check it out.

 

[Head Paneer]

What year and model car does your friend have and has it always been making 4 lbs. or is this a recent occurrence?