1st post here. We have a Peugoet 306 its 3 years old and ours has a plug for the code usb thingy to go in from a laptop. My mate brought a peugeot codes kit from Ebay and he plug it into our car then it brings up the code. I'm not sure yours will have this as its a bit older as you say its from 1995.
We have an engine diagnostic light come up so I will borrow my mates kit. Last time this came on he took the spark plugs out and replaced them then the light went out and now its back on again! Do you think it could be faulty spark plugs as the code kit didnt directly say what it could be.