White_Lightning

HI guys first off im new here nice place.
Im having a problem with my 01 Civic 4dr GX d17a1 non v-tec M/T. The check engine light is coming on and I do know what the problem is it's the lower 02 sensor issue and I'm down in Nova Scotia, Canada so emissions stuff is not a issue I just want to get the power and gas savings back. But I don't want to have to put the stock manifold back on or weld a high flow cat on right now. I have the neo2 but don't want to hook it up till I get some info. I have used the search to get some answers but my question is if I put my new apexi neo2 on my ECU will I be able to get the mil light to go off. I can't really make sense if all the technical terms and fuel curve stuff so right now I really am confused. If any of you guys can give a hand it will make my day I'm getting tired of pulling the ECU fuse and having to do the idle learn stuff I also think it is doing damage to the engine and I don't want to take it to the hillbilly performance shops here cause they do damage to anything the touch.
Also can anyone tell me what I should be getting for mileage I am getting 500k/m per tank is that bad. it also sometimes gives me 400k/m per tank ? that can't be normal the car has a mind of it's own and I don't drive it that hard unless im mad. It has been like that before I put the dc header on and the mil issue started any ideas. I also put bosch v4 platinum plugs in it could that be a problem?
it has the following under the hood.
AEM short ram
DC Sports header
thats it.
anything there might cause a problem?
sorry for the rambling on but I'm at my wits end with the car and I want to burn it lol.
thanks

gearbox

iTrader: (95)

stick with ngk plugs. the secondary sensor does not control a/f mix so therefore has no effect on how the car drives. its for emissions only.