Do catalytic converter need a break in period?

The converter doesnt need a break in period,if you have a check engine light on then you will not pass emissions until it is cleared. I suggest going to emissions anyway before changing the cat because when you fail they give you a 30 day grace period to get your vehicle repaired that would put your mind at ease about getting a ticket. p.s. if you have to have your check engine light reset it may take a couple days for monitors to reset.

I'd drive around for a few minutes (20 or so) just to make sure everything is up to opperating temperature, because cat converters work best at higher temperatures (regardless of if it's new or not) so if the inspection stations on the other side of town you should be fine.

The 20 minute drive is required before any inspection, they won't do it unless the engine has been running at least that long. I was wondering if a longer period was required with a brand new converter.

Good advice. Even changing a muffler shortly before inspections can cause problems from my experience.

ALL CAT'S NEED BREAK IN PERIOD MORON EXCEPT SOME WALKER MADE 1'S...........AFTER INSTALLATION BRING CAR UP TO OPERATING TEMP 2)THEN BRING RPM'S UP 2 2500 FOR 3 TO 5 MINUTES= BRICK INSIDE CAT WILL BE PUT INTO PLACE AS CAT EXPANDS THUS DOING ITS JOB WITH EMISSIONS..................IF YOU DON'T YOU WASTED MONEY AND EXPECT YOUR CAT TO RATTLE..................