Although stainless steel is very durable, it can begin to look worn and tired over time. Stainless steel is relatively impervious to corrosion, but if it is continuously exposed to grit and grime, it will eventually begin to degenerate. Therefore, it's important to clean your stainless steel exhaust from time to time. Consider cleaning your exhaust seasonally to keep it in top condition.
Degrease the exhaust by washing it with warm, soapy water. Dish soap works well for degreasing. Fill a bucket with warm water, add soap and swish it around with your hand. Wet a soft cotton rag and scrub the exhaust until all the grease is gone. Rinse your rag in clear tap water and wipe all traces of soap off the exhaust.
Soak your sandpaper in water for half an hour. Rub the wet sandpaper on the exhaust using a back and forth motion, going with the grain. Sanding the exhaust helps to get rid of tiny particles that have become embedded in the metal over time. Take your time with this step, and thoroughly sand all over the exhaust, using moderate pressure and dipping your sandpaper in water whenever it seems to get dry.
Use a dry cotton rag to thoroughly dry the exhaust after sanding it with the wet sandpaper. Look for any dull areas that might need a little more attention.
Use a clean cotton rag to apply metal polish. Apply the metal polish to the exhaust and vigorously rub it into the stainless steel. The more vigorously you rub the polish in, the greater the shine will be. In addition to helping the stainless steel look its best, metal polish acts as a barrier between the stainless steel and the environmental factors that dull its appearance and eventually corrode it.
Wipe any excess metal polish from the exhaust with a clean cotton rag.
When rubbing the stainless steel to clean or polish it, try to rub with the grain instead of in circular motions or against the grain.
Avoid using cleaning products that contain hydrochloric acid because they will damage stainless steel. Bleach is the most common cleaning product that contains hydrochloric acid. Don't use steel wool because the small steel fibres can get lodged in the stainless steel and eventually rust.