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complete EVAP removal?

37K views 149 replies 19 participants last post by  vortmax 
#1 ·
Who out there has done this????????? As far as the charcoal canister, purge solenoid, lines, ect. So i have been talking about this with a couple of Dakota buddies, and was wondering exactly what all can be removed. i have heard stories that people have done it before, have any of you? Also i have heard that you cant remove it all since there will be vacuum issues which could mess with the breaks some how, is that true? also if ts all removed, is there any way to get rid of the check engine light? Oh and will this cause any problems with the running of the engine?
 
#2 ·
I have done it. You can get rid of the can under the bed, the line up to the manifold and cap it. Also get rid of the censor and use a 1/4 watt 100ohm resistor. It has been about two years since I have done this with no problems. Connect the resistor where the censor clips in and it will prevent any codes. Just make sure the line is free and clear and not caped or plugged that goes to the former canister from the fuel tank. Just cut it and tie it to the frame so it can't get clogged.
 
#3 ·
My mistake, purge selenoid not censor!
 
#4 ·
sweet, that's just what i wanted to hear. so i need to cap off the manifold, get a 1/4 100 ohm resister (can you take a pic of exactly how you did this?), remove the canister, and the only line that needs to stay is the breather coming from the tank? Oh and did your dak have a leak detection pump? If so did you ditch that also?
 
#5 ·
I don't have any pics right now, I did it cheaply and still need to redo it. I simply put the resistor in the connector and electrical taped it still, cause I was in a hurry, it's still holding up. I said to myself once I have a problem with it or if I ever get around to it, I would splice and solder it in nicely. As for the manifold, all parts stores sell multiple size caps and one will be in there to be used, i think it is 1/4 inch. I'm not sure if it had a leak detection pump or what it looks like. But If i have one, maybe I'll remove it:huh:
 
#25 ·
2000s don't have one, my 00' Durango 5.9 doesn't. New thing for 01'+ - I'm still trying to figure it out.
 
#8 ·
I'm at a stump with that part. I know only certian models have that there from what I can remember when doing mine. Or it can be the same as mine, mine is located on the firewall instead. It may be the same part, You can get the resistor for about $1 for 4 at radioshack or any electronic store and even online.

I believe it is the same theory, just located different and or maybe two parts instead of one. Mine looks something like that, but with the electrical connection on it also on top.
 
#11 ·
yeah thats the part then. mine also has electronic conectors on it, and your right, not all dakotas came with it. Thanks so much for the help, any input on removing the AC? thats the next mod after i remove the EVAP.
 
#13 ·
If you have a leak detection pump (thing by the battery) then you are not able to remove the EVAP system. It is a CA emissions truck and much more complicated. I havent tried it but thats what ive been told. Apparently the only way to remove the EVAP system with a CA emissions is to get a PCM from a non CA truck. If you still decide to give it a try let me know how it works because ive been wanting to do it for a while.
 
#15 ·
#20 ·
The evap system pulls and gas vapors from the tank into the engine to be burnt rather than them getting into the atmosphere.
 
#21 ·
2001+ trucks are 50 state emission trucks. There is no more seperate California and federal emissions trucks. The '00 and older trucks are the only ones you can easily remove the evap stuff without throwing a code. I'm sure someone can find a way on the '01+ trucks, I just haven't heard of it yet. And for the R/T forums. Most guys now post on the new DRTC Forums. www.dakotart.com There are still a few stragglers on the Delphi forum, but most check both.
 
#23 ·
like hskr said, all 01+ trucks had the leak detection pump. You can remove it along with everything in the evap system, you will just have a CEL. As of right now, there's nobody that i know of that has removed it and kept the CEL off, but it dosent mess with the engine running in any way, you can remove it and just live with the CEL. Dave downing removed his like 3 years ago, have never had any problems except the annoying light. just make sure you dont cap off the line that goes up to the gas tank, put a small filter on it or tuck it up where it wont get any water/debris on it that could clog it, as it is a small line. If you find anybody that has kept the light off, let me know....i'd like to do it, but havent found a way yet.
 
#28 ·
Well who cares...I just want to get rid of it! lol

Once the battery goes to the rear, that shit needs to come out!
 
#31 ·
Yea so I just unplugged both the sensor plug (two pins/wires) next to the battery and the larger plug under the fuse box. I instantly got a P 1495 code. I'm going to radioshack in a little bit to get the resistors and try it out.
 
#32 ·
Yea so I got the resistor. (1/4 watt 100 ohm) I put it in the leak detection pump harness and the engine light doesn't come on. BUT once I unplug the other thing, I'm not sure what it is (under the fuse box) the engine light comes on (didn't look at the code even though I should of). So now I reset the computer with the reader and put the resistor in the leak detection pump and plugged in the other thing. I start it up and no engine light! Halfway done I guess.

This is the "thing" the fuse box


This is the harness off the "thing" that if it's unplugged, the engine light comes on



These are the hoses off the "thing"
 
#34 ·
Ok I must of gotten it backwards.

It has three prongs...I don't know what to do, maybe try and put the resistors in there?? :huh: I'll be back.
 
#35 ·
Ok so, the resistor thing works for the evap solenoid (what I originally thought its the leak detection pump)





Now, as soon as I discconect the leak detection pump harness, which is three wires (not two) the engine light comes on and throws P 1495.
 
#38 ·
LEAK DETECTION PUMP MONITOR (IF EQUIPPED)
The leak detection assembly incorporates two primary
functions: it must detect a leak in the evaporative
system and seal the evaporative system so the
leak detection test can be run.
The primary components within the assembly are:
A three port solenoid that activates both of the functions
listed above; a pump which contains a switch,
two check valves and a spring/diaphragm, a canister
vent valve (CVV) seal which contains a spring loaded
vent seal valve.
Immediately after a cold start, between predetermined
temperature thresholds limits, the three port
solenoid is briefly energized. This initializes the
pump by drawing air into the pump cavity and also
closes the vent seal. During non test conditions the
vent seal is held open by the pump diaphragm
assembly which pushes it open at the full travel position.
The vent seal will remain closed while the
pump is cycling due to the reed switch triggering of
the three port solenoid that prevents the diaphragm
assembly from reaching full travel. After the brief
initialization period, the solenoid is de-energized
allowing atmospheric pressure to enter the pump
cavity, thus permitting the spring to drive the dia-phragm which forces air out of the pump cavity and
into the vent system. When the solenoid is energized
and de energized, the cycle is repeated creating flow
in typical diaphragm pump fashion. The pump is controlled
in 2 modes:
Pump Mode: The pump is cycled at a fixed rate to
achieve a rapid pressure build in order to shorten the
overall test length.
Test Mode: The solenoid is energized with a fixed
duration pulse. Subsequent fixed pulses occur when
the diaphragm reaches the Switch closure point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5” H20.
The cycle rate of pump strokes is quite rapid as the
system begins to pump up to this pressure. As the
pressure increases, the cycle rate starts to drop off. If
there is no leak in the system, the pump would eventually
stop pumping at the equalized pressure. If
there is a leak, it will continue to pump at a rate representative
of the flow characteristic of the size of the
leak. From this information we can determine if the
leak is larger than the required detection limit (currently
set at .040” orifice by CARB). If a leak is
revealed during the leak test portion of the test, the
test is terminated at the end of the test mode and no
further system checks will be performed.
After passing the leak detection phase of the test,
system pressure is maintained by turning on the
LDP’s solenoid until the purge system is activated.
Purge activation in effect creates a leak. The cycle
rate is again interrogated and when it increases due
to the flow through the purge system, the leak check
portion of the diagnostic is complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.
Evaporative system functionality will be verified by
using the stricter evap purge flow monitor. At an
appropriate warm idle the LDP will be energized to
seal the canister vent. The purge flow will be clocked
up from some small value in an attempt to see a
shift in the 02 control system. If fuel vapor, indicated
by a shift in the 02 control, is present the test is
passed. If not, it is assumed that the purge system is
not functioning in some respect. The LDP is again
turned off and the test is ended.
 
#40 ·
I need info on wiring, voltage and ampage in the wires. Those three wires, I need to know which one does what, so I can figure out it I can use a resistor on them or something.
 
#41 ·
You can unplug the purge solenoid and ptu the resistor in and it won't pop a code as long as the vacuum lines are still hooked up. If you disconnect any of the vacuum lines from the purge solenoid or the ldp, even with the resistor, you will get a check engine light.
 
#42 ·
I'll try this tomorrow.
 
#43 ·
Update...I think I've figured out a way to do this. Update tomorrow!!!!
 
#44 ·
Ok, so chances are there is going to be a relay needed for the LDP harness. Again, thats the four socket prongs/wires. One wire is a ground, one wire is constant power, and one wire is a switched power that goes on/off according the the pressure inside the pump.

I'll be back later with more info, working on this today.
 
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