URD “Off-Road” Y Pipe for 2003+ 4Runner
Fits 2003 and later 4Runners with V6 engine
The stock Y pipe has flow impediments. It has many bends and pinches down to some very small cross-sections. It has a much smaller inner diameter than it looks, The pipe is doubled walled and the inner pipe is very narrow and even more so at the pinch down where it passes under the transfer case.
The lowest part of the truck is where the Y pipe passes under the transfer case and is very prone to getting caught on rocks and stumps when off roading and can get smashed down so much it can prevent the engine from running.
URD was the first to develop the aftermarket Y pipe for the 4Runner and we first did it to solve the off road clearence problem and but quickly realized there is also a nice performance benefit as well.
The flanges have recesses machined into them that are the perfect depth for the gaskets. The stock Toyota gaskets are crushing O-Ring type gaskets. When the bolts are tightened down all the way so the flanges come together, the gasket crushes just enough for a perfect seal. With the flanges firmly flat against each other they don’t move, and they don’t bend causing leaks like some aftermarket exhaust systems and headers do.
The piping is 2.25” high quality, heavy gauge 304 stainless that is extremely durable and all hand TIG welded. This Y pipe will outlast the vehicle.
The URD Competition Y Pipe was designed for off road use and competition events. The rear catalytic converters are eliminated. The URD off road Y Pipe is not for on road use and is absolutely not emissions legal anywhere on public roads.
The URD Competition Y Pipe has ports for the stock rear O2 sensors and has an extra port for an aftermarket wideband O2 sensor for your AFR gauge.
You can install this Y pipe and eliminate the rear catalytic converters without setting a check engine light. The ECU does not monitor the rear cats.
Tests of the Off-Road Y Pipe showed how well it freed up the exhaust system on both stock engines, and engines with a supercharger.