The small diameter piping coming off the main cat , does it need to be blocked off? if not what needs to happen.

Thanks

 

if you have an upgraded ECU i believe you SHOULD be able to remove your air pump and assiciated hardware.(That air pipe you refer to.) also just put rubber caps with hoseclamps on the un used air pump piping. Hope thats close and helps. You may need to fab a block off plate if you take it off at the engine.(backside)

 

Leave it hanging

 

What else need to do when put on the MP besides upgrade ECU?

 

The car will most likely boost creep with a mp, so a boost controller would be a good investment after the ecu.

 

What else need to do when put on the MP besides upgrade ECU?

pick up a box of ear plugs

but it's well worth it to shoot flames at cowering riced out Civic owners