Toyota Camry reported problems:A bad vacuum switching valve (VSV) for the EGR located under the intake manifold could cause the trouble code P0401 in a 4-cylinder engine. Watch thesevideos.The EGR valve itself and other things need to be checked, but often, a new VSV valve fixes the pro...
1998-2008 Toyota Corolla Reported Problems:The Check Engine light with the trouble code P0171 is commonly caused by a failed or dirtymass airflow sensor. Symptoms include stalling and lack of power. Some owners reported that cleaning the sensor solved the problem, others said the sensor had to...