I need to get a emissions check on my 164Q to get it registered in CA. Last time it was checked in June 2008 it barely passed the HC at 15mph with 83 PPM Meas (max allowable = 83) and NO at 15 mph with 673 PPM (max allowable = 689). Since that time the timing belt has been replaced as well as the coils and spark plugs. What items should I check/replace before I go for my emissions check? Thanks.