Check the tightness of the clamps.
Replace noisy exhaust pipes.
Inspect the exhaust system with a light for holes, rusted parts, and worn areas.
Examine the catalytic converter for external damage such as dents and cracks. Tap on the catalytic converter with your hand - the presence of a pulling noise means that the ceramic base of the catalytic converter is destroyed and it must be replaced.
Caution: The catalytic converter may be hot.
Check the rubber holders for porosity by twisting and stretching and replace if necessary.
Shake the entire exhaust system to see if it knocks in any place. If this is the case, loosen all bolts, straighten the exhaust system without tension and tighten all the bolts again.