i have a 1985 firebird 2.8 5 speed and my engine light comes when i drive it for a short period of time so i finaly caught it at my home and i checked the computer and it came up as code 32 EGR Valve i was wondering is it hard to clean? better to buy a new one? and i read somewere to use carb cleaner on it didnt sound like a good idea to me so i took the EGR valve off and it had like sludge/oil? in it? is that normal?