If you want the letter of the law according to your warranty manual from DC the answer is YES. But who is to know unless they remove the side sills. By using Simms or RT cats that include a ********* for the rear O2 sensor. Also note that the rear O2 sensor is between the primary and secondary cat therefor you should not throw a trouble code if the install is done correctly. But in the end it is the call of the DC dealer who is going to warranty the work.
Robbie
