Originally posted by Keith Lennop:
...wouldn't I get the CEL right away if that was the case?
No. A constant CEL will not display immediately. A constant CEL only displays if the "error" occurs in two out of three driving cycles. A driving cycle is basically when you start your car, go for a drive, and turn off your car.
This is probably why it didn't display until 24 hours after you installed the Pro-M and Aussie Pipe.
I have read a good amount of posts about add-ons turning on CELs.
A bigger problem is if the add-on prevents your car from passing an emissions test.
