Here's another link directly from the EMB (Environmental Management Bureau) which details the IRR of RA 8749. Jump to page 80 and 89 for the test procedures. Fellow tsikoteers driving diesel rigs can benefit from having a printed copy of these instructions in their rides, ready to be whipped out if in case they get flagged by the ASBU.

http://www.emb.gov.ph/portal/Portals...%202000-81.pdf