A simple way to test for this prior to removing the cat. You can check pressure at upstream O2 sensor bung or just simply remove the sensors and drive with a hole in the exhaust and see if performance changes.
Yeah this was a option but unfortunately that O2 sensor was practically welded to the threads with rust lol. I don't have a torch, just tons of pb blaster and a 5 foot pole when I got the cat off the exhaust.A simple way to test for this prior to removing the cat. You can check pressure at upstream O2 sensor bung or just simply remove the sensors and drive with a hole in the exhaust and see if performance changes.