Our 2002 Escape initially got pretty good mileage; we could count on 20 mpg, and would get 25 mpg on long trips. It’s EPA rated at 18/23, and we usually averaged about 20.
Over the last few months, however, we’ve been getting about 16 mpg. It runs fine; starts easily, runs smoothly, has plenty of power, and we tend to drive it gently. It’s just that I’m not sure I can take much more of this 16 mpg garbage.
What should I check on it? At 145,000 miles, should I routinely change the oxygen sensors/cats/EGR valve/something else?
The sensors are TOO bad; about $30 each.
The CEL is NOT on.
I meant, “The sensors AREN’T too bad…”.
Sorry.
One thing to check is if the thermostat is stuck partially open.
If it is, the engine doesn’t get hot enough for engine management system to go into the closed loop mode. So the engine operates as if it’s cold all the time with a rich fuel mixture.
Tester
What about the good ol’ basic tune-up ?
When was the last time for plugs, fuel filter, & air filter ?
All that stuff is pretty new.
However, I did notice one item that gets discussed frequently at Ford forums (and not just for the Escape): The DPFE sensor. This is a $37 part, and you can change it in about 15 minutes. Looks like a lot of people are saying it works to change it out.
Some people were even getting as little as 12 mpg. That’d stink…
As an aside, I’d never heard of a DPFE sensor before today.
My Writing professor told me you cant use an accronym before you at least use the full version once. for the public,what does DPFE stand for and what does it do?
Differential Pressure Feedback EGR.
If there’s no Check Engine light on, this is not the problem.
Tester
Normally I’d agree with that, but people are changing the sensor even when there’s no CEL, and it fixes the problem (at least according to forum posts I’ve read…).
I’ve repaired vehicles for over 35 years, and can’t see where DPFE sensor would effect fuel mileage. All this sensor does is measure the EGR valves position under variuos engine operating conditions. Could you provide a link to a site that explains how this sensor would effect fuel mileage?
Tester
I took a 8600 mile trip and kept getting progressively worse mileage . dropping from low 20s to as low as 12 . After I got back the check engine light came on and showed a code for the oxygen sensor. I changed the sensor an the mileage went back to the 20s. So, I learned that the ox sensor(s) can make your mileage drop before they set a code.
There’s a whole thread here:
Ford’s official wording:
“2000-02 Taurus/Sable; 2001-02 Crown Victoria, Focus, Mustang, E-Series, Escape, Expedition, Explorer, F-150, Ranger, Windstar, Town Car, Cougar, Grand Marquis, Mountaineer
MIL illumination with DTC P0401, P0402, P1400 or P1401 and/or rough running, low power, surge and poor fuel economy all indicate problems with the DPFE sensor on the EGR system. If the vehicle has a tube-mounted DPFE sensor and one of these codes are present, the bulletin instructs to install a new sensor, P/N 2F1Z-9J460-AA.”
(For the record, the PN referenced is the one that fits the Escape.)
Okay! I was finally able to open the link.
If you look at the original post, They said “The CEL is NOT on”. If there where a problem with the DPFE sensor, the Check Engine light would be on with a DPFE sensor code.
Tester
Is the oxygen sensor hard to get to?
The O2 sensors are easy to get to.
However, after looking at this job, I decided this is too big a bite for me. Apparently, you have to remove a cross-member to get to the manifold, and without a lift, I am not going to attempt that.
It’s a cracked manifold. These break at the webbing between the “tubes” that lead from the exhaust ports. After several hundred cooling cycles, the difference in the expansion rates leads to cracks. This is one instance where a stainless header instead of an iron casting would have been a better design.
The cracked manifold leads to screwy readings downstream (because of the excess oxygen downstream) which leads the ECU to enrich the mixture, hence the poor mileage.
They’ll install new sensors when they change the rear manifold.
yes that would be it, the oxygen sensor… sometimes sensors are neglected but most of the time replacement for this is the solution…