My 2004 Tahoe threw a P0442 code

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2591tdj

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Vent valve is $13, purge valve is $20, canister is $80, all AC Delco. The hoses are unlikely to suddenly start leaking imo. Start with the cheapest of the 3 or do both valves to start.

Edit: I didn’t see where he eliminated the purge or vent with a Tech 2?
Those look like Rock Auto prices. I paid double that at Auto Zone for their Duralast valve and solenoid. The canister is also about $60-70 higher at AZ. I needed them right away and had to buy them locally.

After installing both valves and disconnecting the battery for 10 minutes, the check engine light was still on when I started it up. How do I get it to go off? Or, could there be other problems (canister, fuel cap, leak in hose)?

I went back to Auto Zone as I heard that they will reset the codes. They said that they aren’t allowed to do so. I’ll try Advance Auto.
 
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Rocket Man

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Those look like Rock Auto prices. I paid double that at Auto Zone for their Duralast valve and solenoid. The canister is also about $60-70 higher at AZ. I needed them right away and had to buy them locally.

After installing both valves and disconnecting the battery for 10 minutes, the check engine light was still on when I started it up. How do I get it to go off? Or, could there be other problems (canister, fuel cap, leak in hose)?

I went back to Auto Zone as I heard that they will reset the codes. They said that they aren’t allowed to do so. I’ll try Advance Auto.
Those are Amazon prices. I have Prime so most stuff comes in one day. You can reset the codes with a basic ODB code reader or they will reset after a few drive cycles. Or go to another auto parts store.
 

2591tdj

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Those are Amazon prices. I have Prime so most stuff comes in one day. You can reset the codes with a basic ODB code reader or they will reset after a few drive cycles. Or go to another auto parts store.
I have bought many vehicle parts on my Prime account but I tend to forget that I can buy parts on Amazon. Thanks for the reminder.
 

Big Mama

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The big parts stores aren’t allowed to clear codes anymore. They may have a “loan a tool” scanner you can use or buy the cheap one for about $15 on Amazon. I used that one to clear my evap codes.
 
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ueww40

ueww40

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Here is how it ends. On my last post I said that I did an extensive smoke test and all the lines seemed to check out fine. I replaced the purge valve, the vent valve and the gas cap, had the code cleared at a Advance Auto Parts store, driven the car almost 1300 miles in 1 1/2 months time and the check engine light stays gone. So I count my blessings and keep my fingers crossed. The light may come on in one of these days or it may not, but so far it appears that the problem has been fixed. Thanks y'all for your help,advise and good ideas.
 

Rocket Man

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Here is how it ends. On my last post I said that I did an extensive smoke test and all the lines seemed to check out fine. I replaced the purge valve, the vent valve and the gas cap, had the code cleared at a Advance Auto Parts store, driven the car almost 1300 miles in 1 1/2 months time and the check engine light stays gone. So I count my blessings and keep my fingers crossed. The light may come on in one of these days or it may not, but so far it appears that the problem has been fixed. Thanks y'all for your help,advise and good ideas.
Glad you got it resolved hopefully!
 

Big Mama

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Same here. I think I heard something like 50 or so on/off cycles would clear it if you didn’t so it sounds like you got it.
 

Madmax02

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Great that you fixed it. I had this problem twice on my 2005 Tahoe. Both times the problem was the charcoal canister. I used to fill my gas tank up all the way up to the gas cap. Especially if gas prices were low! While listening to Car Talk one day, they stated not to do this because the canister can’t vent properly and the charcoal gets saturated. So I stopped filling my gas tank up to the gas cap and just stopped when it automatically stopped. The problem has never reoccurred.
 
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