Not sure what you mean by an igniter amp? Do you by chance have and mean an igniter unit? If so if you have then a quick fix would be to get into the cover and clean up the connections. A YRV turbo owner has had misfiring and reported doing this cleared up the issue. Could also be a MAP sensor issue. Have had this when the car was cold and you get above 2000 rpm the car would misfire.

Edited to add link to a similar issue;

http://www.daihatsu-drivers.co.uk/node/18467

Not cheap, one on Ebay for a YRV Turbo @ £199!

http://www.ebay.co.uk/itm/Daihatsu-YRV-Turbo-Igniter-Unit-Bracket-Part-19200-97404-000-New-/221410136987?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item338d12939b