Issues w/ making a dual exhaust into single?

A few months ago I bought an Flowmaster Dual exit exhaust from a member here who lied to me and sold it to me with missin pieces so now the driver side rattles like crazy!!! If I were to drop the exhaust piping on the driver side and cap it at the muffler do you guys think it would cause any issues with back pressure? I think tubing size is 2.5 on it.

The other pain in the ass part is the second pipe runs right around the rear axle blocking the drain plug and sits about 1/16in away from the Spare so premature wear/rubbing is another issue I face

ANy thoughts on making a dual exit a single?

 

ideal I would like this set up

 

It is a dual exit muffler so capping one of the exits will most likely decrease flow. My suggestion would be to weld another muffler in with single exit, or you could see if a shop can merge the dual exit into one.

 

i feel like merging two into one would cause turbulence in the pipe. Im talking about capping it like an inch off the muffler to try to avoid that