DIY: Fix for P0442
#1
DIY: Fix for P0442
This is a fix for the P0442 Code: small leak in the evaporative emissions system. This can be a pretty frustrating problem, as even a very small leak will trigger the code and Xmas tree on your dash. Sometimes, a tech will just tell you that your gas cap is loose and clear the code. I discovered the leak by adding a small amount of pressure to the evap system using a hardware store air regulator valve. Then I sprayed everything down with soapy water to locate the source. Due the nature of the problem, I figure a LOT of xB owners will deal with this at some point, especially those in the salt belt. Even if you don't find the leak, if you have this code, I would perform this fix or at least inspect the VSV.
1. Jack up the rear and secure in a safe manner. Locate the Evap canister box under the car. The leak was at the VSV attached to the canister. Looks like this (some items disconnected for clarity).
The VSV is held on by a screw into the box and 2 bolts up top that will probably break upon removal. It's a good idea to spray them down with WD-40 and letting it soak in for a day or so.
I broke mine anyway and ended up using a zip tie to hold everything in place. Take off the hardware and remove the VSV by pulling it out of the box.
2.Gently secure the VSV in a vice as shown and use a chisel and hammer to bend the tangs that hold the unit together out of the way.
3.Carefully take the valve apart, noting the orientation of the plastic end to the solenoid and order of parts inside.
This is what you'll find.
Solenoid body:
Valve seat, valve, spring, O-ring (Note:parts not in order in pic):
4.Obviously, the O-ring wasn't designed to seal against rust, so we're going to clean that off with a suitable instrument/sandpaper.
5.With my finger, I smeared a thin layer of silicone onto the bare metal. Silicone isn't exactly compatible with fuel, but we're dealing with a small amount of vapor here so it should be fine.
You just need a small amount here. Don't glob it on there, it will get into the valve, probably triggering another code.
6.Put VSV back together. Assemble the parts into the plastic section and lower the solenoid straight down on top of it. Ensure the valve inside seats correctly when you join them back together.
7.Crimp unit together by bending the tangs back down with large channel locks or the vice.
8.Test the VSV by blowing air through it with your mouth. With 12v applied to the connector, it should block airflow. If it doesn't, you probably assembled it wrong.
9.Reinstall the VSV and put everything back together. Clear the code by removing the EFI/ECU fuse under the hood for a few minutes.
Most guys will just replace the VSV. I figure this is a better solution since the thing will just rust again once exposed to salted roads.
____
1. Jack up the rear and secure in a safe manner. Locate the Evap canister box under the car. The leak was at the VSV attached to the canister. Looks like this (some items disconnected for clarity).
The VSV is held on by a screw into the box and 2 bolts up top that will probably break upon removal. It's a good idea to spray them down with WD-40 and letting it soak in for a day or so.
I broke mine anyway and ended up using a zip tie to hold everything in place. Take off the hardware and remove the VSV by pulling it out of the box.
2.Gently secure the VSV in a vice as shown and use a chisel and hammer to bend the tangs that hold the unit together out of the way.
3.Carefully take the valve apart, noting the orientation of the plastic end to the solenoid and order of parts inside.
This is what you'll find.
Solenoid body:
Valve seat, valve, spring, O-ring (Note:parts not in order in pic):
4.Obviously, the O-ring wasn't designed to seal against rust, so we're going to clean that off with a suitable instrument/sandpaper.
5.With my finger, I smeared a thin layer of silicone onto the bare metal. Silicone isn't exactly compatible with fuel, but we're dealing with a small amount of vapor here so it should be fine.
You just need a small amount here. Don't glob it on there, it will get into the valve, probably triggering another code.
6.Put VSV back together. Assemble the parts into the plastic section and lower the solenoid straight down on top of it. Ensure the valve inside seats correctly when you join them back together.
7.Crimp unit together by bending the tangs back down with large channel locks or the vice.
8.Test the VSV by blowing air through it with your mouth. With 12v applied to the connector, it should block airflow. If it doesn't, you probably assembled it wrong.
9.Reinstall the VSV and put everything back together. Clear the code by removing the EFI/ECU fuse under the hood for a few minutes.
Most guys will just replace the VSV. I figure this is a better solution since the thing will just rust again once exposed to salted roads.
____
Last edited by MR_LUV; 08-17-2021 at 12:31 PM. Reason: Awarded 15 Yr Badge
#2
Should be note worthy that any one in a State with smog regulations that include
visual inspection this can cause you to fail if it looks like you've tampered with the VSV.
___
visual inspection this can cause you to fail if it looks like you've tampered with the VSV.
___
Last edited by MR_LUV; 08-17-2021 at 12:20 PM. Reason: Awarded 10 Yr Badge
#6
It does not seem like this thing is still on. At any rate, I tried this fix and may have done it successfully. I took it out for a test ride afterwards and drove about 60 miles, well past when the three lights come back on. Time will tell, tomorrow I have a nice road trip to see if the fix is in. Thanks for the assist.
#7
Right on for me
When I first started tracking the 0442 0446 codes I pulled off the hose from the VSV and noticed rusty dust inside. Seemed to me that this should not be a place where there should be rust. I sprayed rust remover inside the VSV and and drained it and operated the valve 30 times with a 12V power supply. This made the code go away for a couple of months. Eventually it came back . Now that I've read your procedure this confirms my suspicion that rust was interfering with the operation of the valve. My quick fix did not remove enough rust. Now I will follow your fix.
Great!
UPDATE: I did the fix and solved the code problem!!!
When I separated the valve halves, I broke the rubber O ring seal; It was enlarged and not sitting in the channel. After cleaning off the rust with a Dremel Tool wire wheel
I put a light bead of orange RTV sealant in the gasket channel. I reset the seal in place and trimmed excess length. I put another light coat of RTV sealant over the O ring seal and reassembled.
I broke both bolts that held the solenoid to the canister when removing. I unhooked the electrical connector, a few hoses and unbolted the canister. I drilled through the broken bolts and reassembled
with self tapping screws. Drove 300 miles, checked for Codes with analyzer: no Codes, none pending = FIX. 1/2 hour job.
___
Great!
UPDATE: I did the fix and solved the code problem!!!
When I separated the valve halves, I broke the rubber O ring seal; It was enlarged and not sitting in the channel. After cleaning off the rust with a Dremel Tool wire wheel
I put a light bead of orange RTV sealant in the gasket channel. I reset the seal in place and trimmed excess length. I put another light coat of RTV sealant over the O ring seal and reassembled.
I broke both bolts that held the solenoid to the canister when removing. I unhooked the electrical connector, a few hoses and unbolted the canister. I drilled through the broken bolts and reassembled
with self tapping screws. Drove 300 miles, checked for Codes with analyzer: no Codes, none pending = FIX. 1/2 hour job.
___
Last edited by MR_LUV; 08-17-2021 at 12:24 PM. Reason: Update
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