Hindi po bawal ang after market pipes as long as they comply with the minimum requirements of a working muffler...
Canister ( No cracks, no missing rivets, no holes)
Resonating tube ( Inner tube used to modulate the sound of the sound)
Fiber ( Used to muffle the sound emitted by the engine)
Now, the regulation set by the LTO is 115Db based on ACL-2009-018 and should be measured by a decibel meter...
Without that process of measurement, they cannot apprehend riders based on "tanchameter" readings only... That makes the apprehension subjective...