The problem is if you clear the codes a P1000 code will show up, and they will fail you, thats a tests readiness code, you have to drive about 50 miles so all the tests run and the code goes away.
Does the car run smoothly? its possible to get false misfire codes...but like they said, fresh plugs, fresh wires. Then get the codes read again and see if its there.
2007 Shelby GT500 705RWHP/708RWTQ
2000 Mustang 3.8 A4 TT 450RWHP/475RWTQ 10.996@127 17psi stock 3.8
2006 F250 CC 4x4 6.0L 14.3 @ 93
2006 Mustang 4.0 M5 Vortech 13psi 395RWHP/374RWTQ wife's car