Loss of power

Hey Lads and Ladies I Drive a 1992 Peugeot 205 and have noticed a sudden loss of Power, i Dont have a rev counter ( its Like that from the factory) but it Sounds Like its roaring now where it was way more silent before (past certain speeds, acceleration ist way slower) Before i give Up on my engine im gonna try to Change Air and Gas Filters, Gas pump and the cat is on my list. Any other ideas? Brought the car 3 months ago.

Thanks in advance