96 PA Check Engine Light is Blinking

I have a 96 Park ave., its a 6cy , just the standard not the super charged, it has 120,000 miles, my question is the check engine lite is blinking, the car is still running, but it is very ruff when in drive, my husband said it sounds like a dead cylinder, god I hope not, in any event could it be a sensor or something not so serious? Is there any thing I can check ? I know its best to get it on diagnostic machine but I am not able to at this time, any suggestions?:confused:

When was the last time you had a tune up? How many miles?

Blinking means you are possibly damaging the caytlic convertor!!

How long has the check engine light been on. Was it just solid it at first? You could have a dead coil pack or stuck EGR valve or both at the same time. ince its a 96' you can just go to Autozone or Advance Auto or any national auto chain annd the should check codes for free.