Quote Originally Posted by FoSHO99 View Post
01+ goes into a CAT diagnostic when the rear 02 is deleted by code. It will sometimes cause the LTFT's to fluctuate back and forth and may cause the car to surge, it is testing the CAT. The only way to disable this is to run an 02 emulator or install the rear 02 so it is not directly in the exhaust stream or disable this diagnostic using a program called tiny tuner.

It doesn't run this test at all times, just when it feels the need to run this test, then goes back to normal.
That explains my surge issues,thank you so much. Will have the tune modified,seriously I thank you.