I just bought an 03 WRX a few weeks ago, and I've put about 2k miles on it. It had a CEL code for catalytic efficiency below threshold because of the up-pipe, and I took it in to see what could be done to solve this. I ended up having the shop do nothing to the car because I found out about the resistor mod that would solve the CEL.
Anyway, after I got my car back that day(after paying $106 for diagnostics), I started hearing a gargle like noise when I pull out in first and sometimes when I shift into 2nd at low RPMs. I'm not sure what it is or if it did it before and after I took it into the shop.
Also, sometimes when I'm pulling out in first it seems like it's having split seconds where the power is cutting out and it's like I'm tapping the breaks while I'm accelerating. I've never owned a WRX before, so I don't know if that's a normal occurrence for the 2.0L.
Any help would be appreciated!