P0440 code, now MDS not working

[markabby]

2011 1500 92k miles.

The other day it threw a P0440 code. I cleared it and it came back on, but i noticed two things: first, the MDS isn't working, and, my gas milage actually improved by 2 mpg. I checked out the causes of this code and i realized it's not a big deal since it's only a small leak in the vent line somewhere.

But, I'm lost over the MDS not working and better gas milage. Is there any relationship with this code and the other stuff?? I should be happy about both, but that damn light on the dash is bothersome.

Any suggestions? I know it's kinda weird. I should tell i did add one quart of Marvel Mystery oil to my engine....would that have anything to do with it?

 

[Lyle Longboat]

Well, it is a mystery in a bottle. I have no clue but I’m sure someone will chime in.

 

[Michigan BIGHORN]

2011 1500 92k miles.

The other day it threw a P0440 code. I cleared it and it came back on, but i noticed two things: first, the MDS isn't working, and, my gas milage actually improved by 2 mpg. I checked out the causes of this code and i realized it's not a big deal since it's only a small leak in the vent line somewhere.

But, I'm lost over the MDS not working and better gas milage. Is there any relationship with this code and the other stuff?? I should be happy about both, but that damn light on the dash is bothersome.

Any suggestions? I know it's kinda weird. I should tell i did add one quart of Marvel Mystery oil to my engine....would that have anything to do with it?

Can't see why the Marvel would cause that but then again I don't know everything. I have the same year truck with 114k on it and I turned my MDS off with a tuner and yes my mileage improved as well but I have other mods too. I like the fact that it runs around 1500rpm on the highway ensuring plenty of oil pressure to keep those lifters lubed.
Put a piece of tape over the light lol

 

[markabby]

i thought about the tape, ha ha, but the wife drives it and if everything isn't perfect, she has a fit.

i'm just trying to figure out if the vent line code as anything to do with the MDS. I agree, the MDS is a pain at times.

 

[Tach_tech]

MDS and the eco light being displayed are disabled when the cel is on. P0440 is also not necessarily a leak. It’s a general evap system failure.

These are the possible causes.


EVAP PURGE SOLENOID VACUUM SUPPLY
EVAP PURGE TUBE OBSTRUCTION
OBSTRUCTION IN THE VENT HOSE OR FILTER
ESIM ORIENTATION OR INSTALLED INCORRECTLY
LARGE EVAPORATIVE EMISSION LEAK
ESIM SIGNAL CIRCUIT OPEN
ESIM GROUND CIRCUIT OPEN
EVAPORATIVE SYSTEM INTEGRITY MONITOR (ESIM) SWITCH STUCK OPEN
EVAP PURGE SOLENOID
POWERTRAIN CONTROL MODULE (PCM)

 

[ram1500rsm]

From my observations in other applications equipped with the same technology, 4cyl only seemed to help when you could keep your vehicle in a flat road. I've been running without it for the past 40k miles or so. (i disabled it via tuning). Don't miss it one single bit. Wish we had the option to say no to having such a POS feature.

 

[markabby]

MDS and the eco light being displayed are disabled when the cel is on. P0440 is also not necessarily a leak. It’s a general evap system failure.

These are the possible causes.


EVAP PURGE SOLENOID VACUUM SUPPLY
EVAP PURGE TUBE OBSTRUCTION
OBSTRUCTION IN THE VENT HOSE OR FILTER
ESIM ORIENTATION OR INSTALLED INCORRECTLY
LARGE EVAPORATIVE EMISSION LEAK
ESIM SIGNAL CIRCUIT OPEN
ESIM GROUND CIRCUIT OPEN
EVAPORATIVE SYSTEM INTEGRITY MONITOR (ESIM) SWITCH STUCK OPEN
EVAP PURGE SOLENOID
POWERTRAIN CONTROL MODULE (PCM)

ugh...really? it drives OK and i'm not losing any gas milage, in fact it seemed to have improved. Can i still drive it? we're taking it on a 600 mile drive tomorrow.

 

[Tach_tech]

Should be fine, shouldn’t cause any issues with driveability but definitely should get diagnosed.

 

[markabby]

OK...thanks! i'll get it fixed when we get back.

 

[indept]

There will be a ton of members here causing an intentional evap leak so they can shut the hated MDS off.