P0471 Error Code when in ECO mode

[sbreech]

I have a 2021 STX 2.7 4x4 that I use to tow our 6000 pound airstream. Current mileage is 35,000 and I always run 93 Octane from Marathon. I am now replacing my THIRD Motorcraft EGR Pressure Sensor. The truck is almost always in regular mode or tow/haul mode. But just before I received the P0471 code the last time, and had to replace the EGR Pressure Sensor, I thought to myself, "I figure something happens after I put it in ECO mode to try to save a couple dollars, I'm going to have to spend money on a repair." I was sort of joking to myself. That drive was about a 75 mile freeway drive with no trailer, so I figured ECO mode would be the way. Well, yesterday, I drove my camper to Jackson Center, about 80 miles away, in tow/haul mode. No problems at all. Driving home, I thought to myself, "Lets see what fuel mileage I can get," and put it in ECO mode. 20 miles later, check engine light. I get home plug in my laptop, run Forescan, and what do I see? P0471. I'll swap out the sensor when it arrives Monday, and it'll be fine again. What a pain in the butt.

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[HammaMan]

I couldn't see running in eco mode being any more of a culprit for your issue than if you were eating a bag of doritos. Drive modes remap throttle curve and shift points, some change drive configuration like rear diff lock and 4wd mode. Spark and fuel are going to be run at optimal values for conditions, always. The motor isn't going to lean burn or anything special.

 

[ks54703]

Had a 16 2.7 EB 3.55 gearing and pulling my V nosed enclosed trailers were the reason for jumping to a 18 max tow vehicle.

Now drive a 22 XLT 302a 2.7 EB payload package truck which has a GVWR of 6900# along with 3.73 gearing that handles the enclosed trailers, small dump trailer along with a 22' Lund Baron much better than the 16 ever did.

Rarely exceed the 65mph speed rating on the trailer tires and at 20K vehicle miles all is good.

If you keep your vehicle in high boost for extended times while pulling your trailer is that a possible way to damage a EGR sensor ??? Or are the replacement sensors just failing because of low quality control ???

My guess try to remember your routine prior to the codes to see if there is something in common prior to the sensor failure.

 

[sbreech]

If you keep your vehicle in high boost for extended times while pulling your trailer is that a possible way to damage a EGR sensor ??? Or are the replacement sensors just failing because of low quality control ???

My guess try to remember your routine prior to the codes to see if there is something in common prior to the sensor failure.

Good ideas / points. This time, I towed about 80 miles, mostly flat land, so not continuous boost for long periods. Coming home, same route (reversed of course), about 20 miles into the trip, CEL popped up.

The second time it occurred, I had been driving about 30 miles when I decided to go into ECO mode to save fuel on a 50 mile trip, again, in central Ohio, so fairly flat. I drive like a grandpa anyway, and I was trying to eek another .2mpg. A few miles into it was when the CEL popped up that time.

I'd like to think I'm getting quality parts since I purchase directly from a Ford dealership and purchasing OEM parts, but who knows. I'll go out and swap out the part at lunch - it only takes about 5 minutes - and snap photos of the old and new side by side.

I don't know what's causing it, but if it's an expendible item like an old PCV valve, I'll accept that. I seem to be getting about 17.5k miles on each one, and they're less than $50....

 

[sbreech]

Here are the comparisons.

I used several q tips soaked in isopropyl alcohol to clean out the old one. There was a lot of carbon buildup. I tapped it on the towel and several healthy chunks of carbon came out prior to the Q-tip and alcohol wash.

I think I'll keep this one and see if it will work when the new one fails down the road.

Time to replace? Less than 5 minutes.

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