How to get the car to relearn idle after cat removal?

My cat had been rattling for a little while, so I ordered a new one, but before it got here I decided to hollow out the old one. I put it back on the car and started it, idled fine, maybe a little rougher, but nothing bad.

Went for a drive, and a few minutes in it felt like the car had a missfire, sitting at a light the idle would drop down real low and bounce around a bit, wouldnt pull hard either.

Turn the car off, went into a store, come back 1/2 hour later, same deal, starts fine few minutes later feels like it has a missfire.




The car has RK-Sport headers and a hooker muffler, the cat had ~105,000 miles on it. Is it possible that it was so clogged that the car is having trouble running without it?


I hear you can disconnect the battery cable to get the computer to "forget" everything it had stored in the idle table, but how long does this have to be?

Just a coincidence and I have a missfire somehow also?
thanks
sorry its kinda long
-Ted

I hear you can disconnect the battery cable to get the computer to "forget" everything it had stored in the idle table, but how long does this have to be?

30 minutes but overnight to be safe. Disconnect the negative terminal of course ;)

Pull the PCM BAT fuse for about 15 seconds to reset the PCM.

The more you idle/drive it, the faster it will learn.

THe OBD II computers learn faster than the OBD I's. -From what I'm told.

And yes, 15 second disconnect for that. I was tought 5, but 15 isn't a big differance...

THe OBD II computers learn faster than the OBD I's. -From what I'm told.

And yes, 15 second disconnect for that. I was tought 5, but 15 isn't a big differance...
15 give a margin of error for those that cannot measure time well. :D

15 give a margin of error for those that cannot measure time well. :D


Thanks for the confidence,;)