[fliprayzin240sx]

I tapped mine in the collector but ideally your supposed to tap the hottest cylinder but like said, theres no easy way of telling which. Ive been told if your not sure, tap the cylinder thats closes to the FPR. If your car runs lean due to fuel issue, its the furthest cylinder and closes to the FPR that will have the least amount of fuel causing it to lean out. For SRs, the FPR is up front so #1 will lean out. For KA, the FPR is in the rear so #4 will lean out.