Hi, Guest
It depends on the engine. The seocndary cat on the 2.0/2.3L Duratecs is literally the California emissions cat - there's no sensor attached to it, it just does "extra scrubbing" and power robbing to meet Cali emissions. On Cali and other "Cali emissions" cars, one of the exhaust pipes after the secondary cat measures O2 and the slight detune on those motors reflects the extra emissions compliance effort.
That's why I had zero complaints about removing it on my 07 when I was at MBRP and we were "re-engineering" their exhaust offerings.
On the 3.0L Duratec V6 for Fusion/Escape and others? Not 100% sure yet. I've checked out the exploded parts diagram I got from Stockfish and I've thrown the truck on my ramps... there are three major modules aft of the y-pipe/flexpipe area, and I'm fairly sure that the first one is a secondary cat. I didn't see any sensor wires so I'm assuming for now that it's the same design concept as the 4-cyls. I need to clarify the parts with the Parts desk at Stockfish before going ahead with my redesign. It IS coming, howeverr. ;)
That's why I had zero complaints about removing it on my 07 when I was at MBRP and we were "re-engineering" their exhaust offerings.
On the 3.0L Duratec V6 for Fusion/Escape and others? Not 100% sure yet. I've checked out the exploded parts diagram I got from Stockfish and I've thrown the truck on my ramps... there are three major modules aft of the y-pipe/flexpipe area, and I'm fairly sure that the first one is a secondary cat. I didn't see any sensor wires so I'm assuming for now that it's the same design concept as the 4-cyls. I need to clarify the parts with the Parts desk at Stockfish before going ahead with my redesign. It IS coming, howeverr. ;)
Daily driver 1: 2007 Jeep Wrangler Unlimited Sport "S"
33" BFG Mud-Terrain KM2s, lots of Rough Country gear - bumper, 2.5" lift, swaybar disconnects, Superwinch 10,000lb winch, Detroit Locker in rear D44 axle, custom exhaust, K+N filtercharger, Superchips-tuned.
Daily driver 2: 2006 Subaru Legacy GT
COBB Stage 1+ package - AccessPort tuner, COBB intake and airbox. Stage 2 coming shortly - COBB 3" AT stainless DP and race cat, custom 3" Magnaflow-based exhaust and Stage 2 COBB tune.
33" BFG Mud-Terrain KM2s, lots of Rough Country gear - bumper, 2.5" lift, swaybar disconnects, Superwinch 10,000lb winch, Detroit Locker in rear D44 axle, custom exhaust, K+N filtercharger, Superchips-tuned.
Daily driver 2: 2006 Subaru Legacy GT
COBB Stage 1+ package - AccessPort tuner, COBB intake and airbox. Stage 2 coming shortly - COBB 3" AT stainless DP and race cat, custom 3" Magnaflow-based exhaust and Stage 2 COBB tune.