Clutch Brake

Ok, so a few weeks ago, my check engine light comes on and I get the codes Ran -
car was dying when I slowed down / clutch application / brakes - essentially crapped idling.

p0300-304 - Misfire detected in cylinder

&

p1491 - Exhaust Gas Recirculation (EGR) Valve Insufficient Lift

I replaced the plugs, knowing there was probably a bigger problem. Nothing good. Done research and everything pointed EGR valve - popped the hood - EGR was disconnected by its last owner! plugged and car works well for one day and starts again the same questions - I alternate plug and unplug the EGR for a few days - same thing - runs well for a day and then back to the same thing.

So I replace the EGR valve today - A new brand - great races, the engine light disappears - 2 hours later, much the same!

Before replacing anything, I would get some advice - Thanks.

It could be missed and too much fuel is not burned, so the problem come back. The spark distributor is easy to replace. some time, the son of spark plug should be replaced as they age.
Can you check the code again?

Def battery packs or distributor causing misfires and loading of full bottles. ECU errors must be read multiple cylinder misfire, x failures, all kinds of junk. New distributor / coil with a reset ecu