Jump to content

Repeating evap problem

Pitt84

Recommended Posts

Pitt84 Enthusiast

Pitt84

Posted
Posted

I have a 2006 Silverado that has thrown p0449 p0446 p0554 and now p0442 with the p0554. 

Ive recently replaced purge solinoid under valve cover the evap canister and tubing at the gas tank and rerouted it per GM’S TSB and I’ve also replaced my gas cap. I’ve had to replace several canisters over past 3-4yrs and no I don’t live in a dusty environment. But with the frequency of the codes and fixes lately which have been going on every couple weeks since mid to late February I am starting to think that I am missing some underlying problem within the evap system, so any suggestions would be appreciated. This ****** CEL is becoming a real nuisance bc I’ve tested the purge solinoid I’ve tested the canister checked all evap hoses and fittings for cracks and leaks and not coming up with anything....

swathdiver Senior Enthusiast

swathdiver

Posted
Posted
11 hours ago, Pitt84 said:

I have a 2006 Silverado that has thrown p0449 p0446 p0554 and now p0442 with the p0554. 

Ive recently replaced purge solinoid under valve cover the evap canister and tubing at the gas tank and rerouted it per GM’S TSB and I’ve also replaced my gas cap. I’ve had to replace several canisters over past 3-4yrs and no I don’t live in a dusty environment. But with the frequency of the codes and fixes lately which have been going on every couple weeks since mid to late February I am starting to think that I am missing some underlying problem within the evap system, so any suggestions would be appreciated. This ****** CEL is becoming a real nuisance bc I’ve tested the purge solinoid I’ve tested the canister checked all evap hoses and fittings for cracks and leaks and not coming up with anything....

Have you done a smoke test?  Gotta do that to check the lines and fittings from front to back and especially around the fuel tank.  

sefiroxx Enthusiast

sefiroxx

Posted
Posted

Or, disconnect and cap the vapor line at various points to see if problem goes away. If not then problem exists between cap and engine sensor.

 

 

swathdiver Senior Enthusiast

swathdiver

Posted
Posted

When a code sets, the computer stores a freeze frame of the various sensors at the time the code set so you can compare these against the shop manual.  You need a bi-directional tool to see this like the Tech-2.

 

If a smoke test was done and there is no leak, the next likely suspect would be the ECM but the troubleshooting guide should be followed in the factory shop manual and not my guessin'!

mjm-1957 Enthusiast

mjm-1957

Posted
Posted

Get a real scan tool and see what the fuel tank pressure sensor is reading. If that sensor is skewed you can replace everything in the evap system and still have a problem. We change them all the time. Should be reading 0.0 with the engine off and key on. Next start the engine and command the vent solenoid to not venting  and the purge solenoid to about 50%  and watch what the FTP sensor does. It should slowly start showing a vacuum.If it doesnt move or is not smooth and linear  then it should be replaced. If the sensor acts normal then perform a purge and seal test. Get the vacuum in the tank to about 50% and seal the system with the scan tool,should hold vacuum for around 30 seconds with no leakage, if thats normal watch how fast the vacuum bleeds off when you open the vent solenoid, should bleed off fairly quickly to 0. Hope some of this helps.

L86 All Terrain Senior Enthusiast

L86 All Terrain

Posted
Posted

Not sure if the 800's were the same as the 900's but my 2010 had a long plastic hose that went from the evap canister by the gas tank up alongside the frame rail to the transmission, then it routed up over the trans and clipped on the passenger side of the trans. There is a sponge type filter attached to this hose by the trans. Mine was full of dirt and sand and plugged up. I changed this and my purge can and my CEL went away after clearing. Forget the fault code, this was 5 years ago now. Worth a quick look anyway, hope it helps. 

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • PhilB
      No 12v outlets in 2026 gmc Sierra

      By PhilB · Posted

      It is possible to add your own 12v outlet to your truck.  Check out this video:   I verified via GM Upfitters that pin 31 is the same on the 1500 trucks.  The wire is GM part number 84779405.   You can get the GM 12v outlet from Amazon  https://www.amazon.com/Genuine-Accessory-Receptacle-25774623-13549530/dp/B0F1H9YRGF EWAY 12 Volt Power Adapter for GM   https://www.amazon.com/EWAY-Chevrolet-Silverado-Cigarette-Ignition/dp/B0915RRW6Q/ref=sr_1_1?   I just haven't figured out a good place to put the 12v outlet in my truck.   Some people are getting USB-C to 12V adapters  https://www.amazon.com/WYMECT-Cigarette-Lighter-Socket-Adapter/dp/B0F87WNQKB/ref=sr_1_1_sspa? Not sure if they provide the correct amperage that a device like a tire inflator would need.  
    • Core-Lokt
      Wiring Help, Please

      By Core-Lokt · Posted

      Thanks; I looked there a few minutes, and I think I can find something. I really never looked there, as I thought it was stuff like PTO/aftermarket bodies/accessories like snow plows.
    • newdude
      2 speed transfer case optional now?

      By newdude · Posted

      This is a 1/2 ton thing ONLY.  All HDs 2020-2026 have the two speed transfer case, with Autotrac as an option.     1/2 tons 2019-2026, regular 4x4s come with a single speed case (no 4LO!), and trucks with Z71 ordered, or all Trail Boss trucks come with the 2 speed case.  2 speed case is also an option on WT, and is also standard on High Country.  
    • newdude
      Different requirements for oil filters?

      By newdude · Posted

      2013 5.3 still to this day calls for the PF48 filter.  Which as a 15psi bypass pressure.     There is a TSB, 17-NA-157 that talks about the PF-63 and PF-64 filters which have a higher bypass rating of 22psi.    TSB HERE - temp.xml   "Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of pump out pressure. This means that the oil pump now does not begin to regulate until pressure is built up to the main gallery. This change reduces the amount of time it takes to provide oil to the engine bearing and lifters during extreme cold start conditions.  Main gallery feedback oil pump control systems are present on the following engine families which use Spin-on oil filters: Small Gas Engine (SGE), Large Gas Engine (LGE), High Feature (HFV6) Gen2 and Small Block Gen5 gasoline engines. These engines with the main gallery feedback oil pump control systems are factory built with an ACDelco® oil filters"   It also calls out what engines use those filters.  The gen 4 small blocks were not on that list (LMG, LC9, L9H, L92, L94, L20, L96).  Gen 5 small blocks use the higher pressure filter.          That all said...   Your 7045 Napa filter is the PF63 equivalent, with 22psi bypass.  You are already using the higher bypass pressure filter.  You CAN keep using it, you don't technically have to use it though.  
    • Grumpy Bear
      Different requirements for oil filters?

      By Grumpy Bear · Posted

      Do you know WHY the filter relief setting was increased to 22 psig?    When the new system goes into the second stage the pump volume ramps up considerably. It was found that the 15 psi filter bypass setting put the filter in bypass on a warm engine when the second stage was activated. Raising the filter bypass setting forced the filter to do what it designed to do. Filter. Preventing debris from circulating during high load, high rpm operation.    So next question is how did GM find this out? VLOM/lifter failures and a deep dive by Melling Corp.    Last question. Is it required? Look at it like this; a motor may be equipped with a rev limiter. But it only works if the set point in reached. That 22 psig setting only matters if the pressure differential across the filter media exceeds 15 psig during normal warm operation. Second stage kicks in around 3000-3500 rpm.    I can't answer your question because I don't know you and how you use the truck. But I think there is enough information here to let you decide for yourself. 😉

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...