S2000 Catalytic Converter Removal and Test Pipe Install
By Rob Robinette
If your car is a track only vehicle or you can get away with running without a catalytic converter, installing a test pipe in its place will free up your exhaust flow and add a few horsepower. The swap will also drop a few pounds from your curb weight. If your state does an emissions visual or exhaust sniff test your car won't pass with a test pipe installed. Many states simply download your OBD II data and the 2000-2005 S2000 will usually be ok and not report problems to the emission inspector. But 2006 + cars get more Check Engine Light triggers with a test pipe so it could be a problem.
The Finished Product
I got my test pipe from Berk Technology www.berktechnology.com for $110. Part S2000 00-07 Cat Delete Pipe w/ Built in O2 CEL Fix. The small pipe protruding from the side is for the catalytic converter's oxygen sensor. It will help prevent the Check Engine Light from illuminating.
From the Berk Technology Website
Cat Versus Test Pipe
22mm wrench or oxygen sensor socket (pictured below) to remove the cat's O2 sensor
Two 12mm wrenches to remove the spring bolts at the front end of the cat
14mm socket or wrench to remove the 3 nuts at the rear of the cat
9/16 & 11/16 sockets or wrenches to install the provided nuts and bolts at the rear of the test pipe
1/2 inch breaker bar
Liquid Wrench or PB penetrant
Standard 22mm (7/8 inch) Oxygen Sensor Socket
Start by jacking the car. If you only raise one side the driver side will afford easier access to the O2 sensor. Make sure the car is secure and chock the wheels before crawling under it. As soon as you can spray down all the fasteners with Liquid Wrench or PB penetrant and let them soak. Remove the O2 sensor first while the cat is still firmly attached. I used the above 22mm (7/8") O2 sensor socket and a 1/2 inch breaker bar. Be careful not to damage the two electrical leads going to the sensor.
Remove the Oxygen Sensor
I used the breaker bar to break loose all five of the cat's fasteners. You'll need a 12mm deep socket for one end of the spring bolts (pictured below). Remove them all and push the cat rearward. The rear end of the exhaust system will move rearward and allow you to drop the front end of the cat down, then slide the other end of the cat free.
Two 12mm Spring Bolts
Other Side of the Spring Bolts - 12mm Deep Socket Needed Here
Removing the Spring Bolts - Both Ends are 12mm
Three 14mm Nuts Secure the Aft End of the Catalytic Converter to the Exhaust
The Berk test pipe comes with 3 new bolts for the aft end, but you use the two original spring bolts on the front end. Before you crawl under the car with the test pipe notice that the three bolt holes in the aft end are not symmetric, the gasket will only fit one way. I applied a little Lock Tite Red (high strength) on the 3 supplied aft bolts before assembly. To keep the spring bolts and O2 sensor from seizing in place I put some anti-seize paste on their threads. Be careful not to get any of the paste on the O2 sensor's probe, it will ruin it and cause the Check Engine Light to illuminate.
Put the new gasket in place on the test pipe, push the pipe into place (aft end first) and bolt up the aft end, then install and tighten the original spring bolts. Once the cat is secure install the O2 sensor by pre-twisting the electrical wires before you screw it in. You do this so you don't leave the wires twisted after you screw it in.
Cat Test Pipe Bolted in and Ready to Go
Be sure and keep your catalytic converter so you have the option of reinstalling it someday.
Enjoy your enhanced exhaust.