I have a 2002 Acura MDX with a 3.5L engine. I have a code PO 401, insufficient EGR flow. I have 132,000 miles. What can I check?

 

Your EGR port is probably clogged. You need to clean your intake manifold. There is big writups in the TL 2gen forum on this site. Pretty sure there is a DIY laid out. Just search Seafoam and there should be lots of threads on it. It's a common problem with our cars. Hopefully this helps. I took my intake manifold apart and really cleaned it and then i run seafoam in the gas and also run it thru the vaacum port about every 3000 miles. Thanks F1

 

EGR valve or EGR ports.

 

EGR ports have to be cleaned. Its a bit different from a TL/CL. Those have a different intake manifold design from that of the MDX.

There are not parts that have to be replaced actually.... you can clean the plenum cover gasket where the carbon deposits collect.

Let me know if you need any help.