engine light on PO401 code diagnosed

Question

Engine runs well. Suddenly this light came on. Got oil changed, got code diagnosed and light was reset. Light not coming back on yet . 1996 toyota Camry with 101,000 miles.
Have had catalytic converter replaced months ago. Mechanic said not worth getting checked but our teen is driving this car and want to be safe. Should we take it to toyota dealer or is it something to not be concerned about? Or is it something we can fix ourselves if needed.

Answer 1

P0401 EGR gas flow insufficient

There are several ways to approach this code condition . If the EGR is not block due to carbon, You can have a problem with the EGR transducer. or the EGR vacuum regulator solenoid. or even the thermostat being in the stuck open position. This code you have is a important  , what the EGR does is cool the combustion chamber to control NOx. Depending on the engine size, you can put a hole in the engine piston on the No. 2 cylinder.which will end up costing a replacing the engine.

​ EGR vacuum transducer

​ EGR vacuum solenoid