High Flow Cat Install question 4.0 SOHC

[sandsprayer]

I finally replaced the catalytic converter with one on eBay, brand new made by magnaflow.

Yeah Yeah- nero'd thread, but the only way I would buy a MagnaFlow piece off Ebay is if it was from MagnaFlow's store on Ebay.
Good chance it's Chinese knock off crap, hence the poor performance?

 

[CDW6212R]

I have looked into cats a few times, and it's obvious that there are many levels of quality, efficiency, plus different airflow restrictions. It is very hard to select a universal cat, I leaned towards Flowmaster cats the last couple of searches I did. Those were in the $75-$140+ range.

 

[valenciaismail]

It is interesting that you would lose mileage from a new converter. I wonder if the brick design was more restrictive than OEM.

Speed Test​