Originally Posted by Urbanengineer

I planned to keep the downstream sensors in the art pipes, do you think that will cause codes because of the downstream restriction?

Originally Posted by Urbanengineer

Tony mentioned running no cats until after the engine break in was finished. Makes sense. Lots of assembly lube when putting it back together.

Originally Posted by cleric670

I've seen HFC's mounted completely at the rear, basically mounted where the mufflers would usually be. It's not a bad location too since there's a lot of room and plenty of factory installed heat shielding. These cars didn't use a muffler though, resonator and HFC only.

The only downside would be routing the wiring for your downstream sensors, I'd pull it back up into the cabin, route through the interior to the trunk, then dive down to the underside of the car. I don't know if it would affect tuning out efficiency codes (I doubt it) but maybe @seymore4 could shed some light on if there's any issues with that far of a distance between upstream and downstream sensors.

Originally Posted by Urbanengineer

ART pipes don’t tend to throw codes, so I am hoping I will be okay.

I’ll run without them during the break in period and then install after the break in is done.