IM thinking about putting a set of shorty header on my 87 Chevy pickup. It now has stock manifolds with cross over pipe. The 02 sensor is on the drivers side manifold. I was going to weld an adapter above the collector on the same side. Add another converter and run dual instead of the crossover. Will this mess with my emissions at all. It's a late 87 model so it does have EFI and is not carbed.