My 88 CRX DX has been acting up. It no longer runs, but in it's final moments it would sputter in low rpms with almost no power and it backfired close to it's demise. I saw that oil was in the spark plug cylinders, and I changed the o-rings for them about 7 times. everytime I changed them it would run fine for a few weeks, then return to it's unstable condition. The last time I did this, nothing changed. I also replaced the spark plugs several times, and cleaned out the plug wires. I assume it's a cracked head or bad head gasket, any thoughts?