Evaporative (SHED) and exhaust emission tests were performed on 20 latemodel catalyst-equipped vehicles to investigate the effect of three preconditioning procedures consisting of: (1) no preconditioning, (2) 1975 FTP driving schedule, and (3) 10-minute road route. A failure analysis was also performed on several vehicles which were found to either have high evaporative emissions or evaporative emissions which were higher than similarly equipped vehicles.

"EPA-460/3-77-013." "Contract No. 68-03-2412, Task Order No. 3." "EPA Project Officer: Gary M. Wilson." "August 1977."

Introduction and summary -- Conclusions -- Methodology ; Vehicle selection and procurement -- Vehicle test sequence -- Vehicle preconditioning -- Evaporative emission tests -- FTP exhaust emission tests -- Quality assurance procedures -- Failure analysis -- Data analysis -- Data recording and reduction -- Data analysis and interpretation -- Effect of preconditioning on evaporative and exhaust emissions ; Analysis of failed evaporative emission control systems -- Appendix. Assessment of vehicle emissions in the in-use vehicle population depends upon a reliable and repeatable test procedure. This task order was initiated to investigate the effect of various preconditioning techniques on evaporative and exhaust emissions. This information will be useful in determining the appropriate test procedure for use in emission-factor test programs. Evaporative (SHED) and exhaust emission tests were performed on 20 late model catalyst-equipped vehicles to investigate the effect of three preconditioning procedures consisting of: 1) no preconditioning, 2) 1975 FTP driving schedule, and 3) 10-minute road route. A failure analysis was also performed on several vehicles which were found to either have high evaporative emissions or evaporative emissions which were higher than similarly equipped vehicles.