P1404 BUICK -

Question

Just purchased a 2001 Buick Century. SES light came on and checked codes. The check came back with P0404 and P1404 codes. I understand that the EGR valve may be dirty or need replacement but what does the p0404 code mean and what needs to be done to clear it,

Answer 1

Hi there

Both of these codes mean the same thing. One is the generic OBDII code. P0404, the other is the manufacturer specific code. If you clean the egr valve and the egr ports, it should resolve both codes.