tomorrow i have to put gas in it. then that should trigger the nvld test and i will drive it to see if anything shows up. being the system had some pressure in it from the smoke test and i did not see any smoke until i took things apart i think i have a sealed system. the nvld looks like it may be the culprit. thanks

 

ok i took it out just now and put half tank in it and the codes about cleared. i have the egr and the cat yet to clear. don't know how long they will take, maybe someone here has an idea on how long those take to clear out once a dtc has been reset, as that clears out the i m readiness monitors. i expect to get the p0420 for the cat inefficiency as it has 1 pending but that may have been set by all the other codes, my cobalt got that code because of the wire to the canister was broken as soon as i repaired that the p04290 went out.

tomorrow i have to go places so i will drive it and see if the cat and the egr clear out. so if they do then my problem was the nvld and yours may be also. thanks

 

ok the update. did the smoke test and it passed. i then changed out the nvld and that looks like it was the issue. i took the old one apart and the switch had corrosion on the solder joints and i believe that was the issue all this time. it any codes return that are evap related i will return and update this. but after i replaced the nvld the codes started to drop off fast. the last ones to go was the cat and the egr, they dropped out today during the road test and im monitor reset trip.

on another note for those that have the thumping/rattle noise in the front when hitting small bumps i got that repaired today also. what i did was take a pc of heater hose cut it about 2" long slpit it into 3 pcs lengthwise and then loosen the sway bar holding screws and i slipped the hose section under the mount to make it squeeze on the sway bar some more. took it for a ride on known areas the caused the noise and it is gone. if you lift the car and look at the rubber mounts you may see the gap in the bar and mount. by squeezing that area you take the play out and it will quiet down. this may not be a permanent fix but those mounts are bear to remove contrary to some youtube videos that say they are easy. took me all of 3 hours to get the right one off and then back on and slipping a section inside the mount. so the left side i slid it under the mount serves the same purposes good luck on thant if you go for it.

i have a cobalt that the front lower arms would blow out the bushings and i did a similar thing to that and they have held up nos for 6 years.

 

Congrats! Sure beats spending the money on converters as you were first dredding about! May not have been an outright EVAP leak, But def. an EVAP issue on the cat efficiency DTC!

 

thanks rebel59. it took some time and research but also i had to coordinate the repairs with my girls schedule and the weather. she needs it for the kids every other week and then we had snow in the last few weeks she was going to bring it over and did not want to be driving a strange car. she had to have the awd car and now she has it gas mileage and all.

i will know for sure in a few weeks if this was the actual repair if no evap codes return.

what made me think i may have had some type of defective part and not a leak was my cobalt all of a sudden sent me a bunch of codes the evap the p0420 and a bunch more and all it was, was a broken wire on the sensor on the canister. fixed that wire and the codes went away. and with all the codes this car gave me i was thinking i had a bad part, one reason o got the nvld. i tried smoking it last fall using the gas filler and an old cap and did not find any leaks but i was not confident it that smoker so i make another one and got the opportunity to use it on the cobalt during that code setting it did 2 weeks ago and it worked great. so this time on the pacifica it worked great. now we all know. thanks again.

 

I had the same codes..... 0457 I believe and it ended up being my fuel pump nipple breaking off. You can drop the fuel tank on the back side down just enough to take a looking. Also you can use a scope and see what the fuel pumps look like. first thing I would do is change the gas cap with a mopar gas cap. If you need some more info you can PM me .

 

Gentlemen, great write up! You seem to know way more than any of the shops around here or probably even the dealership when it comes to Pacificas.
Got a quick question, my Pac will not allow me to fill the tank properly. Have to just trickle the fuel in very slowly, if I try to fuel at a normal rate the Pacifica's tank belches air out, tripping the fueling dispenser off.
Very frustrating and time consuming to fuel this car up. Would you think that a failed NVLD is the problem? Many thanks!

 

More likely a plugged EVAP canister or (if equipped) fuel tank vent valve.

 

the nvld has a filter on it and up along the driver side frame rail the vent has a cap on it. you can remove the filter and take that to the bench and see if it is plugged up as well. that is a real easy task to see if it is what you have. or just take it off for a fill up and see if that made the fillup better if it did then the filter or cap was plugged. myself i would take it off and see then just put it back on if not plugged, then what rebel said may be one more thing to check. i think that requires to take the tank off.

jjfits84 i made an access hole in the floor to access the right side pump and the nipple on mine was perfect and the connector tube was plenty lose, it may have been repaired sometime ago. thanks all items help when someone is in need of ideas. i for one welcome all ideas and then get to pick the one that works for me.