2000-Up Cadillac DeVille Dual Rear Exit Exhaust System w/ Twin Pro-Series 3.5"

For ease of installation and safety concerns, the use of a lift is recommended and be sure to wear safety glasses. Prior to installation, be sure vehicle is parked on a level surface and the exhaust system is cool.
1) After your vehicle is properly secured and there is enough clearance to work from under the vehicle, the first step is to remove the oxygen sensor located between the catalytic converter and the center muffler - (See Fig. A). Use a 7/8-inch open-end wrench to remove the threaded sensor.
2) The next step is to determine where to cut the connecting pipe between the catalytic converter and center muffler. Using a tape measure, measure from the front edge of the catalytic converter flange (See Fig. C) back 20 INCHES for the STS or 18-1/2 INCHES for the DTS and mark the connecting pipe.
NOTE: Recheck your measurement
3) Using a saw or chain-style pipe cutter, cut the connecting pipe at the 20-inch or 18-1/2 inch mark depending on vehicle.
4) The next step is to remove each rear muffler from its hanger bracket. Use a 15mm socket wrench to remove the nut holding the top of the rubber insulator to the hanger bracket shaft.
NOTE: Be sure to keep the rubber insulator and nut from each rear muffler as they will be needed for the installation of your new mufflers.
5) Next, slide one of the rubber insulators off the Intermediate Pipe hanger bar.
6) Now the complete exhaust system can be removed as one piece. Once the system is removed, slide the rubber insulator off each muffler hanger.

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