txf54

I just replaced my O2 sensor and cat (had nasty **** rattling around in it) and I've noticed a smoother transition of power, but only after I replaced the O2 sensor. Is this normal? Or is it probably because of the new cat?
​​​​​​Thanks 👍

dave1123

If it was rattling, the matrix had probably collapsed and was blocking the pipe somewhat. Did you check your muffler for pieces in it?

txf54

Yeah, when I cut the cat out we inspected the muffler and it was all good

jordan96xj

Yes, it is normal. A failed or failing O2 sensor will cause the air fuel ratio to be improperly adjusted by the computer. This can lead to a variety of power related problems (stalling, stumbling, sluggishness, etc.). So correcting the air fuel ratio (by correcting the faulty sensor) can seem like getting a lot of power/smoothness back.

Jeepwalker

The computer is calibrated for a certain amount of O2 'drift' over time. But eventually the electrical signal becomes weaker. Installing a new one restores the signal. Ideally one should disconnect the battery and hold the cables together, to reset the computer, but it should eventually square itself after it does some learning. I'm going to replace mine tool