CEL: P0402

I have a CEL on and the code is P0402 which is excessive flow to the EGR. My MPGs are down ever since it came on by 2-3. I checked all of the vacuum hoses, replaced the EGR, replaced the VSV, replaced both 02 sensors, and replaced the catalytic convertor, muffler, and tailpipe. The CEL persists. Any other ideas? It is a 1996 Tacoma with 281,000 miles, 2.7L 4 Cyl, 4x4, extracab. Thanks in advance.

 

It could be the EGR modulator is bad.

When I had a 0401 code (insufficient EGR flow) it turned out to be the EGR temp sensor (it informs the ECM about the amount of EGR flow that is detected). Check if that sensor is still connected properly.

 

Have you checked your throttle valve to make sure it's opening enough to expose EGR port. Might be worth a look.