Another great mod to go with a tuner/afc would be a WIDEBAND O2! I wish i would have had one of these a long time ago. If you have a laptop the Inovative motorsports LC-1 is a great choice. It's only $175 too and it will alow you to dial in your afr with out having to guess with the stock narrow band 02's the indicate leaner as your rpm climbs.