P0300 and P0302

Computer problem 4 cyl Front Wheel Drive Automatic 101900 miles

Well, as a former mechanic this is embarrassing, but I still don't know what the problem is and I need help.

It all started when I noticed that the engine ran just a little rough at idle. Soon after that, the check engine light came on and the code was P0302 "misfire at cylinder #2" and before I could do anything the light went away on it's on so I ignored it.

Later, the light came on again I checked it and it was the same code. I replaced the plugs and the cables, erased the code and it all seemed fine. Later the light started flashing so I scanned the car again the this time it was the old code plus P0300 "multiple random misfires".

I replaced the coil and cleared the code. It all seemed fine until at a stop light the "mil" came on flashing once again. At this point I am lost without a freaking service manual in order to know what to look for. I can think of several things that can be causing it but I need info in how to troubleshoot my car the right way. I have limited funds and it will be impossible for me just to replace parts and hope that was the problem.

When I drive, the light is on but not flashing, then when I get to any stop the light starts flashing. I am sure that the engine senses the unburned gas and it does not want me to ruin the catalytic converter. So it makes the light flash.

Please help me I really depend on that car. I am thinking that it could be the crankshaft position sensor but then again why only when the car is idle? Also why it is telling the that is cylinder #2.

Ideas anybody? Thanks for your help!