DPFE Sensor Hoses Reversed?

[John Carrigan]

Hello everyone. I have a 1994 Mustang with the 3.8 L engine. Tonight the
check engine light came on even though all the gauges, etc. are fine. I
hooked up a reader to the OBD II port and received an error code of P1403. I
looked up the code on the various websites and this is what seems to be the
most common explanation ; P1403 Differential Pressure Feedback EGR (DPFE)
Sensor Hoses Reversed . But could this hose reversal symptom be a sign of
something else? I haven't done any thing to the engine for a few months
except the regular oil changes and stuff like that. One person says it may
be dirt or carbon in a hose. I thought that if anyone would know a Mustang
it would be you guys ( and gals!) .

TIA for any advice you have.

[Jim Warman]

First thing to do is clear the code and see if it returns....

The DPFE "expects" to see low pressure (vacuum) on the "downstream" port
(closest to the intake) and higher pressure on the upstream (exhaust side)
port. Early DPFEs were prone to failure and this may be the cause of this
concern... You're choice... replace the DPFE and reassess or perform some
testing and, quite possibly, come up with a faulty DPFE.

Important to consider... if nothing else has changed... no tampering - no
nothing.... the DPFE is the most likley cause of this concern since this
same sensor is used to judge the coherency of the sensor...

YMMV....

Top postingly yours......

"John Carrigan" <moon...@hotmail.com> wrote in message
news:13n8npu...@corp.supernews.com...

[John Carrigan]

Thanks for the reply. I'm also starting to think it needs to be replaced.
But I was wondering if there is any damage it could cause by driving it to
the auto parts store to get the part? I'm guessing it would maybe burn more
fuel and mess up the performance, but could it normally cause any serious
damage to the motor? The store is only a few miles away so I'm not worried
about gas consumption.

Thanks again!

"Jim Warman" <mech...@telusplanet.net> wrote in message
news:lt1dj.42587$UZ4.4493@edtnps89...

[Jim Warman]

No other damage, as a rule... These things have been failure prone in the
past and it is rare to see any bad side effects (if any) from driving with
the concern present.

[John Carrigan]

Thanks, that's great to know, I didn't want to blow anything up!

What I did was take it off and check the hoses, they seemed clear and clean.
It looks like the original metal one, so being as it's probably 13 years old
I figured there might be gunk or corrosion inside. I have a spray can of
stuff I use for my electronics, it's called Electrosolve Contact Cleaner. It
leaves zero residue and is safe for contacts, pots, optical filters,
circuits, rubber and plastic. It's also great for displacing moisture. I
soaked the inside of it, turned it right side up to drain out the extra and
put it back on the motor. I also soaked the contacts and plug. When I
started it up it ran noticeably smoother and I've done about 70 miles of
city driving, up to 2 hours at a time, and no more engine light on or any
more codes.

I'm going to take your advice and just replace the thing. Maybe in the
spring when the weather clears I'll do the EVR and EGR just for piece of
mind.

But as a side note, the DPFE can be expensive in this area. The dealer
wanted $195 for one but a local auto supply store called NAPA wants $117 for
one.

Thanks again for everything!

"Jim Warman" <mech...@telusplanet.net> wrote in message

news:pFHdj.50954$5l3.40558@edtnps82...