my girlfriend has a 99 sL2 and the exhaust is leting go at the back of the resonator. I was going to cut it out and weld in a straight pipe and prolly put in a glasspack in there to keep the noise down. my question is does anybody know the diameter size of the pipe i will need to complete the job? it looks like 1 3/4 but not sure

Yes, 1.75" OD is correct.

Yes, 1.75" OD is correct.
thanks for the quick reply i appreciate it