I have a question about my 1998 Toyota Camry . It would not start when the outside air is humid. Check engine light is on, OBD code was EGR – insufficient airflow code P0401.
When the humidity is normal, the car starts and runs well. Could the EGR system be the culprit or is an ignition problem. ? Thank you very much.
I would say this is probably NOT an EGR problem, but rather an ignition issue. I would first check to see if there is moisture inside your distributor cap…around your ignition coil and spark plug wires. I am assuming this is not a distributorless engine.
Since you say outside moisture plays a factor, I would want to concentrate my efforts around the distributor and ignition coil. I would also have someone crank the engine over on the next moist day AS you watch the distributor and spark plug wires under the hood for any arcing sparks.
If it’s been more than 50,000 miles since you have changed the spark plug wires, distributor cap and ignition rotor you might want to consider replacing them anyway as maintenance.
Keep me posted as to what you find out.