Just hoping that there is something common that causes this problem. This thing can idle just as smooth as you could want one to and the next time it will have a dead miss, and the miss is not consistent. It may miss like three hits then be ok a little then miss a little. There is no CE light or codes. Again just hoping there is something common.

 

Whens the last time you changed your plugs and wires? Could have a slit in one of the wires.

 

Actually it now has a CEL and the code is P0133 which is the oxygen sensor. Will that cause some back firing and a very sluggish engine. It slowly keeps getting worse.