engine light flashes

flashing check engine light mean a misfire is happening and it could be damaging the cat. but the repetative pattern like u say is odd but it could be coincidental is the engine shaking sputtering or anything like that?

Engine is sputtering..... n I know I have to replace the cat just was trying the fuel filter first n now since the fuel filter was changed it is worse, looses all power n sputters when I excelerate then stops when I release.

you have to check everything but im thinking it got worse because the fuel filter was partially clogged and it was holding back all or most of the crap from the tank when u put the new one on it opened up and let more crap from the tank to the engine. did the old filter look like it was pissing out brown fuel ? i think the pump is finally starting to go. get a fuel pressure gauge on it to see what it is putting out at idle and accel the pressure should be 55 - 62 psi for either engine get the codes read if u can they will be very helpful check for vacuum leaks good spark, check fuel pressure regulator post if u find anything else out

This might help.When the battery is disconnected that will clear ALL the codes.The first time you start it up if it starts flashing right away could be the result f a bad PCM