I have an EF XR6 on gas, recently it has had a bit of a rough idle and a bit of a stumble at low rpm on accelerating. During the week it backfired and blew the air intake apart. I have seen this happen to a few people and it usually means that the ignition needs some attention.

So I bought a brand new Bosch coil pack and put it in this afternoon. After putting it in and replacing the air intake, I started it up and now it has a serious miss, like it is only running on 4 or 5 cylinders. I went out and got new leads and plugs to make sure it wasn't them causing the issue, replaced them, but it is still there.

Is there something I could possibly have missed while putting the coil pack in? I have triple checked the leads are in the right order, all the bolts are done up and the coil pack is plugged in. What are the chances of getting a dead coilpack? I am meant to be going away tomorrow and am desperate to sort it out before I go! Any advice would be really appreciated! Thanks in advance