Check Engine Light P1404 code
Thread Starter
Newbie
Joined: Nov 2018
Posts: 5
Likes: 2
From: Dallas/ Ft. Worth
E-450
Check Engine Light P1404 code
I drove my 2025 E-450 at hoghway speeds for about 100 miles yesterday. I reached my destination and had a nice 40 minute lunch and started up the car and began driving back home. After about 10 minutes I noticed the check engine light—which his hidden behind the steering wheel— was on. All other indications were normal and so I drove home. I took my scanner and found a P1404 code which it says is related to an EGR system fault. Of course, when I started the car this morning to take to the dealership, the check engine light was not illuminated. Since I have a few minor issues that need addressing I took it to them and we’ll see what they find if anything. I
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
Thread Starter
Newbie
Joined: Nov 2018
Posts: 5
Likes: 2
From: Dallas/ Ft. Worth
E-450
Senior Member
Joined: Jan 2021
Posts: 331
Likes: 180
From: The Middle of the Fairway
2025 E450 All Terrain Wagon, Nautical Blue Metallic, Macchiato Beige/Black Interior
I drove my 2025 E-450 at hoghway speeds for about 100 miles yesterday. I reached my destination and had a nice 40 minute lunch and started up the car and began driving back home. After about 10 minutes I noticed the check engine light—which his hidden behind the steering wheel— was on. All other indications were normal and so I drove home. I took my scanner and found a P1404 code which it says is related to an EGR system fault. Of course, when I started the car this morning to take to the dealership, the check engine light was not illuminated. Since I have a few minor issues that need addressing I took it to them and we’ll see what they find if anything. I
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
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Joined: Nov 2014
Posts: 5,393
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.
I consider the purchase price a sunk cost.
Depreciation turns into appreciation after a few years.
In 2023 my W113 (250SL) was professionally appraised at over $100k which was about 20 times the original cost.
I'm looking forward to adding a '27 E class EV.later this year.
Last edited by ua549; Jun 1, 2026 at 02:06 PM.
MBWorld Fanatic!
Joined: Aug 2014
Posts: 1,939
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From: Tennessee
W214 E450
Wow, it only took one reply to take this off topic. A record perhaps.
Back on topic - it could be the exhaust flap issue that has happened to mine and several other E450 owners. I posted about it here. I would not accept that the problem went away just because the CEL went out.
Good luck and let us know how it turns out.
Back on topic - it could be the exhaust flap issue that has happened to mine and several other E450 owners. I posted about it here. I would not accept that the problem went away just because the CEL went out.
Good luck and let us know how it turns out.
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I drove my 2025 E-450 at hoghway speeds for about 100 miles yesterday. I reached my destination and had a nice 40 minute lunch and started up the car and began driving back home. After about 10 minutes I noticed the check engine light—which his hidden behind the steering wheel— was on. All other indications were normal and so I drove home. I took my scanner and found a P1404 code which it says is related to an EGR system fault. Of course, when I started the car this morning to take to the dealership, the check engine light was not illuminated. Since I have a few minor issues that need addressing I took it to them and we’ll see what they find if anything. I
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
If I recall, the inside gas cap door on the E450 (2026) even has a note about this issue.
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Thread Starter
Newbie
Joined: Nov 2018
Posts: 5
Likes: 2
From: Dallas/ Ft. Worth
E-450
Originally Posted by Tseg;[url=tel:9296228
9296228[/url]]My guess is your gas cap was not tight. That can cause an EGR fault. And can be corrected by tightening the cap and driving it around again. When you stopped for lunch did you also fuel up the vehicle? My first experience with CEL related to loose gas cap goes way back to the late 1990's... and I remember the Pontiac dealership charged me several hundred dollars for hooking it up to their scanner to get the code, then tightened the gas cap.
If I recall, the inside gas cap door on the E450 (2026) even has a note about this issue.
If I recall, the inside gas cap door on the E450 (2026) even has a note about this issue.
Super Member
Joined: Nov 2013
Posts: 746
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From: NorCal
2015 ML350+2025 E350
Besides, OP is driving a 2025 model. Sounds like he already made the EV decision.
Junior Member
Joined: Dec 2025
Posts: 27
Likes: 22
From: Chicago
2025 E450
I drove my 2025 E-450 at hoghway speeds for about 100 miles yesterday. I reached my destination and had a nice 40 minute lunch and started up the car and began driving back home. After about 10 minutes I noticed the check engine light—which his hidden behind the steering wheel— was on. All other indications were normal and so I drove home. I took my scanner and found a P1404 code which it says is related to an EGR system fault. Of course, when I started the car this morning to take to the dealership, the check engine light was not illuminated. Since I have a few minor issues that need addressing I took it to them and we’ll see what they find if anything. I
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
i love this car, but it is not the reliable MB I had in my 2019 E-450. I am getting frustrated and annoyed with it. Any thoughts?
I called a couple of local dealers and no one had availability for an immediate evaluation, and my road trip schedule doesn’t allow me the luxury of waiting around for a couple of days even with a loaner, which they didn’t have any available in any case. One service advisor I spoke to said he wouldn’t have any concerns about my driving the car back to Chicago before servicing it. He suspected just a sensor that needs to be cleaned, although this inconvenience seems silly and unnecessary in such an expensive vehicle. After a few days visiting a friend in San Diego, I went to drive back north again this morning, and the light was not on and did not come on at any point during my 8 1/2 hours of driving today, sort of validating the service advisor’s expectation that this is a minor issue. But it’s rather nerve-racking and I hate seeing the light on so I feel your stress!
Thread Starter
Newbie
Joined: Nov 2018
Posts: 5
Likes: 2
From: Dallas/ Ft. Worth
E-450
I find the timing of your post quite coincidental. I also have a 2025 E450 with about 17,500 miles and 14 months of ownership. I am on a long cross country road trip and had my first CEL appearance at the END of a full day drive from Sacramento to San Diego last Tuesday. It went away for a couple days then reappeared. Also have P1404 code with no other errors or issues reported. Car driving normally with no gas mileage issues or rough accelerations. Because I am about 5000 miles from home and not going to return for another three weeks, I of course had concerns about how safe it would be to drive the car all the way back home and then get it seen to by my dealer’s service department.
I called a couple of local dealers and no one had availability for an immediate evaluation, and my road trip schedule doesn’t allow me the luxury of waiting around for a couple of days even with a loaner, which they didn’t have any available in any case. One service advisor I spoke to said he wouldn’t have any concerns about my driving the car back to Chicago before servicing it. He suspected just a sensor that needs to be cleaned, although this inconvenience seems silly and unnecessary in such an expensive vehicle. After a few days visiting a friend in San Diego, I went to drive back north again this morning, and the light was not on and did not come on at any point during my 8 1/2 hours of driving today, sort of validating the service advisor’s expectation that this is a minor issue. But it’s rather nerve-racking and I hate seeing the light on so I feel your stress!
I called a couple of local dealers and no one had availability for an immediate evaluation, and my road trip schedule doesn’t allow me the luxury of waiting around for a couple of days even with a loaner, which they didn’t have any available in any case. One service advisor I spoke to said he wouldn’t have any concerns about my driving the car back to Chicago before servicing it. He suspected just a sensor that needs to be cleaned, although this inconvenience seems silly and unnecessary in such an expensive vehicle. After a few days visiting a friend in San Diego, I went to drive back north again this morning, and the light was not on and did not come on at any point during my 8 1/2 hours of driving today, sort of validating the service advisor’s expectation that this is a minor issue. But it’s rather nerve-racking and I hate seeing the light on so I feel your stress!
