Idle issue

[chance]

I got my new mx-3 last Sunday with a bad motor. I swapped the motor out Monday and I've been messing with the idle unsuccessfully since. I have the idle down to a fairly consistent 1K rpms most of the time, but every now and then on startup the car almost stalls because the revs are at about 200. I got a check engine light that comes on if the car sits idling for a minute or so. I get a 5, 17, and a 24. I think I got a bad knock sensor because of the #5, I've already messed with the wiring and the connector. I don't know what would cause the 17 and the 24. Could the knock sensor cause my idle problem? Anyone have any suggestions?

[lazzyie]

knock sensor could make your car shut off, if you switched motors from different years they may not be compatible so its not the sensor is bad just the ecu cant regonize it, 17 and 24 means your 02 sensors are probably dirty this could also mess with your idle, and make the car run like crap. Good luck

[chance]

Thanks, I'll see what cleaning the O2 sensors does. Brakeklean would be fine to use right?