Tomorrow I should be receiving my new exhaust manifold and I will be putting it on same day. I already went and got my emissions tested just in case something goes wrong, since this new exhaust eliminates the first cat. I already have a greddy catback on my lancer and i was just wondering if anyone who has already done an after market exhaust manifold had any problems like check engine light or running bad in certain conditions? Any input would be greatly appreciated. I haven't been on this site in about 8 months but I will be on regularly and I will update with pics.