Check Engine Light code P0402

[Aurrick]

CEL came on and stayed on. I cleared it by disconnecting the battery for 5 minutes. It stayed off for about 30 miles and came back on.

Autozone's code reader gave one code only: P0402 "EGR Flow Excessive".

The autozone guy said that I needed to replace the EGR valve and clean out the line that leads from the valve to the exhaust. Does this sound correct?

It seems counterintuitive to me. If the EGR flow is excessive, doesn't that mean that too much is flowing through the valve and the line? If the line was clogged with carbon deposits wouldn't the flow be low, not excessive?

2001 Ford Ranger Edge 4x4
4.0L SOHC
57,430 miles

I use regular unleaded 87 Octane, no aftermarket additives.

If replacing the valve is the right way to go, is there anything I have to do besides just put the new valve in? Any adjustments?

Thanks for your help.

Aurrick

 

[TheJMan]

I had the same code on my 5.0. In my case, the DPFE (Differential Pressure Feedback EGR) was stuck open. Not sure about the 4.0L engines, but on mine there are 2 hoses that run from the EGR tube to the DPFE, makes it easy to track down. Plus the DPFE is not terribly expensive either. Had it replaced at the dealer for $80, part cost is about $30.

 

[Diddy74]

I also had a P0402 code, from what I learned the EGR valve could possibly be clogged, stuck open or closed either letting too much in or too little. Also the DPFE could be fried and not making the proper adjustments. I replaced the DPFE, took the EGR off and cleaned it out with carb cleaner until I find a replacement. It made a world of difference as far as idle and smooth acceleration.