Do you have to worry about passing car inspections with an upgraded camshaft?

depends on which state and county....some run a performance test on a dynamometer to check engine performance through the RPM cycles...to check if the EGR is opening up as it should...levels of CO2 (none CO allowed) NOx and water vapor through all driving conditions...if these are unaffected....go for it~

Most recognized aftermarket cam manufactures will have the cam marked as "50 State Legal" which means it has passed the tests for pollution in all 50 states, even the CARB restrictions in CA. If your car or truck is an old one and it is smog exempt, who cares. Most of the older cars are fixed up for weekend adventures or show and not daily drivers so the smog restrictions have been lifted. Custom cams? Check with the cam grinder if he knows the grind will meet smog. It also has a lot to do with what else you put on the motor, carburetors or EFI. The heads and exhaust also come into play. Generally, a commercial cam marked "50 State Legal" will not cause any problems or concern. If you can, take it to a place that will conduct a "pre-test" before hooking it up to your state computers. Fail once and you have issues for years.