Possible Causes
Rich fuel system condition can be caused by leaking fuel injectors, defective fuel pressure regulator, restricted or blocked fuel return line, leaking purge valve, defective purge solenoid, open or short in purge solenoid circuit or defective powertrain control module. To diagnose fuel system concerns, see BASIC FUEL SYSTEM CHECKS (A-7) in appropriate BASIC DIAGNOSTIC PROCEDURES article. To diagnose purge control system concerns, see EMISSION SYSTEMS & SUB-SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.