94 Mustang Gt Miss Problems

[94 gt/cobra]

I have a 94 mustang gt just bought 2 weeks ago. It has been stroked to a 306 has e303 cam, trickflow heads, cobra upper intake, edlebrock lower, bbk throttle body, pro m racing maf. I put new cap and rotor, new 8 mm plug wires, new iridium plugs, new fuel filter, new air filter, new valve cover gasket and plenum gasket, cleaned the maf. The o2s have been bypassed. Has rough idle sometimes not always but when driving anywhere from 1500 to 3000 rpm it misses back fires bucks and acts crazy I have checked all vacuums no leaks it is throwing egr code but it has been deleted as well. I was thinking tps or iac but I wanted some insight before I keep sinking money into it. Also the reason i replaced gaskets I thought I was getting blow by through pcv valve but turned out to be stripped valve cover bolt so I tapped it out and put new gasket.

 

[94 gt/cobra]

Also meant to add I did check the timing its at 13 degrees and if I give it more throttle it cleaea up and runs great only while cruising

 

[Bam Bam]

Yeah I purchased a 95 GTS had similar issues. Mine came with a tweecer installed but was not ever tuned. I spent a month researching and tweaking finally got the bugs out. Are you running a chip with your computer?

 

[2L8ULUZ2]

My first question is why are the o2 sensors bypassed and by what means was that done? The next thing is your issue sounds like a distributor with a pip sensor that is failing. I've had it happen twice in my car and it will eventually die and leave you stranded. The other thing it could be is a bad coil. I am also curious how you got a cobra upper intake to bolt to a Edelbrock lower because the two are not compatible at all.