1993 Toyota Corolla Q&A

1993 Toyota Corolla Question: hydrocarbons

My toyota corolla has hydrocarbons [roughly 200ppm] only at idlιng. The other exhaust gas is normal. Is this normal??? If not what the probable cause??? 730 rpm CO………[%vol]……..0.04 CO2……..[%vol]……..15.79 HC………[ppm]………205 O2………[%vol]……...0.07 λ………………………0.996 2600 rpm CO……….[%vol]……..0.00 CO2……...[%vol]……..15.85 HC……….[ppm]………16 O2……….[%vol]………0.03 λ……………………….1.000 The car does not burn oil. Were checked all sensors and is okay. Ηas a stable idle and good acceleration. -
Answer 1
Can you please post the readings of all the gases measured? As well as the engine RPMs? -
Answer 2
Does your Toyota idle smoothly? If so, does it use oil or smoke, especially on start up? If the car does not idle smoothly, then it could be a misfire caused by worn tune up parts, a sticking EGR valve or valves that are too tight and need adjusting. If your car uses oil, well then that is usually caused by engine wear. Let me know the answers to these questions. I do Emissions work in CA, and have repaired lots of Toyota vehicles. -