insufficient egr flow.
60%of Mercury's do this with a bad dpfe sensor. replace if for good measure, it's bound to go out some time even if it is not right now. you'll need to buy soem hoses for it too, the replacement dpfe isn't shaped the smae as the old one, and requires an extra inch or 2 on the hose to the ref port (you'll see, it's labeled that way on the sensor)
30% are because of blocked passages in the egr system. they get full of carbon and soot, and it probably needs cleaned out. you may have to take off your throttle body to find it, it depends on the engine.
Trouble code P0401 means:Exhaust gas recirculation flow insufficient detected
Trouble code P0401 means:Exhaust gas recirculation flow insufficient detected
Trouble code P0401 means:Exhaust gas recirculation flow insufficient detected
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
Trouble code P0401 means: Insufficient EGR Flow Detected Replace the EGR valve
might be the EGR VALVE insufficient flow
depends on the year. copy and paste the code to see. http://www.racepages.com/parts/radiator/mercury/tracer.html
NEED COLOR CODE FOR RADIO SPEAKER WIRE 93 MERCURY
I have a p0708 code on this cougar 1999 2.5 with a p0420 code also what sensor should i replace
P0401 = Insufficient EGR Flow
Trouble code P0401 means:Exhaust gas recirculation flow insufficient detected
Trouble code P0401 means: Exhaust Gas Recirculation Malfunction