Clicking Noise From Exhaust as it Heats up and Cools Down
There may be a problem with the engine causing the exhaust or converter to run hotter than it should. It could also be the result of a incorrectly -installed exhaust system. However, noises of this type can be normal for some systems.
If the converter is hotter than it should be, have the engine tuned up. If the noise started shortly after installation of a new system, make sure the system is neutralized which means the insulators are hanging straight down with no fore or aft tension.