I bought a scanner for my oddyssey today because check ingine light came on. This is the 2nd time . First time I took it to a machanic , he told me I need to change O2 sensors which he did. That cost me big money. I been doing my tuneup for a long time and I also bought a Haynes Repair Manual. With this code according to the manual my problem is EGR Volve. My ?is if I change EGR VOLve that will solve my problem I don't think changing a EGRvolve is that hard. Any help on this is very well appriciated. Thanks.:confused:

P0401--EGR Insufficient Flow Detected

Replacing the EGR Valve should solve the problem.