so I have codes po 135 po155 po303 po 307 and p1000?? I put new plugs wires and both coil packs on and it still misses pretty bad and once in a while (quite often) the light flashes at me in the middle of all this I had in the shop and had both manifolds replaced bolts rotted off I was too cheap for new cats and gutted them thanks for all your help

 

You have a problem with both front O2 sensors - heater circuit. Either both of them need to be replaced or you have a wiring issue.

What brand plugs, wires, and coil packs did you use? Did you do a compression test?

What year and engine?

 

You 'may' also see codes 420 and 430 with gutted cats, that won't go away until cats are put back on.
Good luck.