The CZP / PPE Downpipes were a collaborative effort between the two companies. These replace the lower catalytic converters, mounted right before the "cat-back" exhaust, eliminating a huge restriction in the exhaust system.
In-house dyno testing was performed on a 3.0tt 300hp variant which was completely stock aside from these downpipes. Not only was peak power and torque increased without performing any additional mods or tuning, but power and torque see noticeable improvements across the entire RPM range. Also of note is that lower downpipes will not trigger a CEL as long as the upstream (primary) cats are functioning normally.
Lower downpipes will only help your engine breath better as you increase boost pressure, upgrade your intakes, and the rest of your exhaust system. The in-line resonators do a great job keeping rasp down. In fact, on our testing car (with a full stock exhaust), it really only sounds louder during hard acceleration. When mated up to free-flowing aftermarket exhaust systems, these will provide a throatier sound than stock cats, without the rasp you get with straight down-pipes.
Please Note: Includes new stainless steel hardware. Gaskets can be re-used if they're still in good shape, otherwise new Infiniti OEM gaskets are available as optional add-ons above. We also offer CZP Upper Downpipes that eliminated the primary cats for even more power gains, but installing them will throw a CEL if you don't also add a CEL-fix to the downstream O2 sensor or turn off the codes in your preferred tuning software.