It is easy to pull and check the regulator once the system is depressurized. The screen on mine was plugged with black goo from paint inside the fuel cell. We blasted it clean with carb cleaner, and I ultimately did the e-clip modification specified in Volvo parts bulletin P-23-7 number 3, version 1. This replaces the screen with an e-clip spacer. I'd say it is worth checking.
