Just to clear up, it isn't a matter of not going over x rpm, but simply drive the car in part throttle. If all is well do a few third gear pulls to see what AFR is doing. When you do these 3rd gear pulls initially, simply do each pull to a higher rpm each time while watching Air fuel. This is how it is done on the dyno when we develop or custom tune a car.
If it checks out to 3K rpm, next pull got to 4K, if that is good, go to 5K etc. That way if you hit a super rich spot or a leaner spot, you don't go through it and you can massage the changes in the software.