97 Taurus riding rough the codes say its my EGR. My uncles' a mechanic and said it could be spark plugs?

Question

I know what the codes mean but here they are any way P0401 P0402 P1405 P0304. Also does anyone know what and where a DEPE sensor is

Answer 1

p0401,p0402,p1405 all deal with the EGR circuit... usually when I see p0401 and a p0402 together that tells me the DPFE sensor is bad (common issue on Fords of this vintage.. need a new DPFE sensor about $100 from Ford dealer as other stores won't carry it usually.. and it's the sensor going wacky from deposits that have built up inside the sensor ..once it goes below 0.2v it sets the p0401,once it hits 5v it sets the p0402....)

The p1405 deals with one of the DPFE's hoses.. probably related to the codes above but my guess is to be on safe side, replace both DPFE hoses as well (same place..Ford.. and these are special hoses made to withstand high temps)

And to clear it all up, the DPFE sensor measures how much EGR flow goes into the motor... EGR is the flow of exhaust gases into the engine to cool the engine cylinder inside to help limit the formation of NOx or Nitous Oxides (harmful to health and is one of the gases that we have to control)


The p0304 is a misfire on cyl 4 or basically the cylinder right behind the power steering pump... could be plugs, could be plug wires,coil, fuel injector, or even some internal to the engine... without diagnosis I can't tell you for sure, but my guess is fresh set of plugs and wires should take care of the p0304 and some of your rough idle... cleaning the throttle body and changing the DPFE will take care of the rest usually (but no guarantee since I can't see the engine)

Answer 2

Basically, if the code is set for the EGR valve, then something happened involving the EGR valve "circuit" - not necessarilly the valve itself. It may not still be happening, but if your engine is "missing" it probably is.
As my father (a mechanical engineer) always used to say, "Check the simple stuff first". So check the vacuum line connection to the EGR valve (EGR is usually found on the upper part of the exhaust manifold close to the engine). Check both ends of the vacuum line and any connections along the way. A cracked hose (likely in a 97) can leak enough to prevent proper EGR operation. They tend to crack near connectors (stress points). Failure is more or less related to age and hours of operation, not necessarilly mileage.
EGR failure mimics spark plug failure because a partially open EGR valve will allow exhaust gas to enter the intake manifold (which it is supposed to do at certain times) at low engine speeds (which it is NOT supposed to do). This results in a lean (or rich) mixture at certain plugs, confuses the oxygen sensor, and can cause a "miss" on one or more plugs - just like a bad plug would do.
Believe the codes. They are correct. Keep in mind that the problem may involve more than what the code indicates but never less.

Answer 3

The DPFE Sensor is located on the right side of the engine close to #1 injector next to the EGR solenoid, on top rear of the intake manifold.
I would remove the EGR valve(only 2 bolts) look inside of it for pieces of carbon and remove pieces if found. Do the same for the IAC valve(idle air control).

Answer 4

The aluminum of the Cly head reacted with coolant in the combustion chamber and the metallic of the spark plug could be inflicting crusty build up around the plug.. Your motor vehicle maximum in all probability needs a head gasket. and on the same time as the pinnacle is of a few gadget keep time to take out the seized in spark plug. i think of you may desire to grant the motor vehicle back to the mechanic. you will be careful paying for automobiles from mechanics or all of us for that rely. Why sell a suitable working motor vehicle?

Answer 5

I had to replace my egr valve and it was expemsive but wirth it
on an almost ten year old car its not the worst thing that could happen
it controls the ammount of gas and air that get to the engine
and it proportions it correctly
my car would work okay sometimes and then when stopping it would stall, this was very dangerous and annoying
you would coast into a stoplight and then it would just die then people honk at you, while you restart... it happened going up hills too, even more dangerous! it would run too rich and flood without this effeciency monitor... mine cost like $300 to replace and put in and that was 2 years ago

Answer 6

I'd go with what your uncle says, first. If that doesn't clear it, then you might have to replace a sensor. I think DEPE is a fuel sensor, but I'm not sure. Sensors are more expensive than plugs, and it doesn't hurt to put new plugs in once in a while.

Answer 7

If it gets better while you accel it is probably the egr the plugs would get worse under accel

Answer 8

if you blew a spark plug you'll have trouble accelerating. the car will shake after like 25 mph. it's not too expensive to repair.