It has a misfire ,we changed the plugs and the coil pack and wires still has a misfire what else could it be
Gas or compression. Check the injector circuit on 1 and 3. Are they pulsing, to put gas in the cylinders? Do a compression test to rule out loss of compression as cause for the misfire.
Kind of odd it would be 1 and 3, but that is one right after the other in the firing order of 1-3-4-2...so, you have a single coil? So you have a distributor-examine closely the distributor cap and rotor if those were not changed too, with the plugs and wires. Look for damage, little black tracks that indicate shorting of the spark, maybe damage at the electrode tips on the inside of cap on 1 and 3 plug wire towers. Most people change the cap and rotor when doing the plugs and plug wires.
Just a possibility also, that the injector ground wires for 1 and 3 might share the same ground. That is to say, they might splice together before going to the computer where the computer internally grounds injector circuits to cause pulsing. Well, those are my thoughts, good luck. And let me know what you find, always interested.