Proposal to delete text requiring integration of electrical current at 20 Hz from GTR 21 para. 5.2.1., simplify requirements for determining and verifying K1 and K2 factors in para. 6.1.1.1. and 6.1.1.2. by deleting redundant sentences and SAE J2907, adding conditional manufacturer reporting on K factor determination, and add a note to para. 5.2.1. stating specific humidity need not be measured unless ICE power correction per para. 6.9.3.2. is applied.