Engine sluggish, does not pick up as it should

[soundman]

New to this forum, and need some help please. Mine is a European Ranger (fitted with the Mazda engine).

Initially, my mechanic thought it was EGR valve problems, as the P0401 code pointed to that.

But the EGR, and solenoid valves have been checked, and everything blown through, no blockages at manifold etc. Engine light still comes on, engine still sluggish. Vacuum hoses have been checked, wiring/connectors all seem OK, also the turbo checked (no damage to fins, or too much play etc).

Mechanic is baffled, as the DTC code seems to have thrown us.

Any thoughts anyone? Thanks.

 

[SenorNoob]

I hate to tell you this, but there aren't many people here with that style of Ranger. I wish you luck in finding an answer.

 

[RonD]

P0401 is insufficient EGR(exhaust gas recirculation) flow, which is almost always a sensor issue.

Newer EGR systems use a DPFE(differential pressure feedback) sensor.
It will have 2 hose connections and 1 electrical connection.
The way it works is pretty simple.
1 hose goes to exhaust manifold
1 hose goes to EGR tube coming from the exhaust manifold
When EGR valve is closed the pressure in both hoses would be the same

If EGR valve opens a bit then pressure in the closest hose would drop a bit, the more the EGR valve opens the more the pressure drops.
DPFE sensor tells the computer the Pressure Difference between the 2 hoses.

So "P0401-insufficient EGR flow" means the DPFE sensor is not telling computer of a large enough pressure difference as EGR valve opens.

Because the DPFE sensor only last about 60k miles it is usually wise to just swap it out if you are near or over 60k, and don't replace with Ford DPFE sensor, 3rd party seem to last longer.

All that being said, fault in EGR system can cause stumbling idle but usually not sluggishness, EGR is suppose to open when accelerating, it cools down cylinders so lowers NOx emissions, diesels are bad for high NOx.

I would look at a Wastegate issue, it can cause higher and lower back pressure in exhaust manifold, throwing off DPFE sensor, causing P0401, and limit boost so sluggishness.