Is it ok to run one test pipe and the other the OEM cat? I broke a o2 bung off my invidia test pipe and want to put the stock cat back on the side that's missing until I get it fixed.
I dont wanna take both off. Put on. Take off. Etc.

Also how bad would it be to run it with only one o2 sensor in with both test pipes?

 

It will function but try to get it fixed soon. Any muffler shop or welding fab shop will be able to TIG weld the bung back on.

 

Ya that's the plan but idk when I'll have time to go down. But thanks for the reply back