P0446 Evap Code

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

bluebear15

Full Access Member
Joined
Dec 27, 2009
Posts
344
Reaction score
41
Location
wisconsin
I recently got the check engine light on my 06 Tahoe Z71 and I scanned it and got the P0446 evap system code. A few months ago I replaced the evap canister and purge valve for having the same code since I was also experiencing where the pump would click off a bunch of times while trying to fill the tank. This time I am smelling fuel fumes from the back by the gas cap area. Wasn't sure if there was more to check for and if there is what to check.
 

915_Tahoe

Your GM Parts Specialist
Joined
Jul 1, 2018
Posts
1,349
Reaction score
1,900
Location
HELL PASO, TX
HAVE YOU CHANGE OUT THE GAS CAP, IF NOT I WOULD RECOMMEND THAT CHEAP AND EASY TO DO. MAKE SURE YOU GET AN OEM CAP NOT AFTERMARKET, THOSE DON'T SEAL AS WELL. YOU WILL HAVE TO PUT MILES ON THE TRUCK SO THE CEL CAN TURN OFF.
 
OP
OP
B

bluebear15

Full Access Member
Joined
Dec 27, 2009
Posts
344
Reaction score
41
Location
wisconsin
HAVE YOU CHANGE OUT THE GAS CAP, IF NOT I WOULD RECOMMEND THAT CHEAP AND EASY TO DO. MAKE SURE YOU GET AN OEM CAP NOT AFTERMARKET, THOSE DON'T SEAL AS WELL. YOU WILL HAVE TO PUT MILES ON THE TRUCK SO THE CEL CAN TURN OFF.

No haven’t replaced the gas cap yet
 

915_Tahoe

Your GM Parts Specialist
Joined
Jul 1, 2018
Posts
1,349
Reaction score
1,900
Location
HELL PASO, TX
this is what i pulled up, let see if it helps

#04-06-04-055A: LR4, LM4, LM7, L59, LQ9, LQ4, L18 DTC P0446 (Restricted/Blocked EVAP Vent Path) Set, Service Engine Soon (SES) Lamp Illuminated (Replace Vent Solenoid and Bracket) - (Mar 20, 2006)
Subject: LR4, LM4, LM7, L59, LQ9, LQ4, L18 DTC P0446 (Restricted/Blocked EVAP Vent Path) Set, Service Engine Soon (SES) Lamp Illuminated (Replace Vent Solenoid and Bracket)

Models: 2000–2003 Cadillac Escalade
2002–2003 Cadillac Escalade EXT
2003 Cadillac Escalade ESV
2000–2003 Chevrolet Suburban, Tahoe
2002–2003 Chevrolet Avalanche
2000– 2003 GMC Yukon, Yukon XL
with 4.8L, 5.3L, 6.0L, 8.1L Vortec™ V8 Engine (VINs V, P, T, Z, N, U, G — RPOs LR4, LM4, LM7, L59, LQ9, LQ4, L18)

This bulletin is being revised to add updated warranty information and enhance the content. Please discard Corporate Bulletin Number 04-06-04-055 (Section 06 — Engine/Propulsion System).

Condition
Some customers whose vehicles are operated in dusty type environments, such as farming or mining off-road type applications, may comment about the illumination of the instrument panel SES light, with a DTC of P0446 (Restricted/Blocked EVAP Vent Path) being set.

Cause
Dirt and dust intrusion into the EVAP canister vent solenoid, resulting in restricted air flow, may cause this condition.

Correction
DO THIS
Replace the EVAP vent solenoid with a more robust vent solenoid.

DON'T DO THIS

DO NOT Replace the EVAP canister or other EVAP parts.

After following the Service Manual diagnostic P0446 and determining that the EVAP canister vent valve is the cause of the SES light, replace the existing EVAP canister vent solenoid and bracket. This new vent solenoid has an enhanced filtering capability and a filter element that can be easily removed and cleaned. To ensure correct installation, follow the procedure below.

  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the bolt retaining the vent valve bracket.
  3. Disconnect the electrical connector.
  4. Disconnect the canister vent valve hose.
  5. Install the new vent valve bracket, P/N 15105605, to the vehicle with the retaining bolt.
    Tighten
    Tighten the bracket mounting bolt to 12 Y (106 lb in).
  6. Install the new vent valve, P/N 10382105, to the bracket.
  7. Reinstall the electrical connector.
  8. Reinstall the canister vent valve hose.
  9. Lower the vehicle.
  10. Clear the DTC.
Parts Information

Description
qty 1.
15105605
Bracket, EVAP Emission Canister Purge

qty 1.
10382105
Valve, EVAP Emission Canister Control
 
Last edited:
OP
OP
B

bluebear15

Full Access Member
Joined
Dec 27, 2009
Posts
344
Reaction score
41
Location
wisconsin
Did you change the 2nd solenoid on the intake also?

I changed the evap canister on the back of the fuel tank and the purge solenoid on the intake. I’m assuming that’s the one you’re referring to.

Do they still sell the non updated one at Advance Auto? I got the AC Delco ones.

The one thing that is leading me to maybe a leak is the strong smell of fuel fumes both by the engine bay and the back by the gas cap/filler neck. Just weird that it would happen a month or so after I changed the Evan canister and purge solenoid.
 

Doubeleive

Wes
Supporting Member
Joined
Nov 7, 2017
Posts
26,126
Reaction score
39,085
Location
Stockton, Ca.
I changed the evap canister on the back of the fuel tank and the purge solenoid on the intake. I’m assuming that’s the one you’re referring to.

Do they still sell the non updated one at Advance Auto? I got the AC Delco ones.

The one thing that is leading me to maybe a leak is the strong smell of fuel fumes both by the engine bay and the back by the gas cap/filler neck. Just weird that it would happen a month or so after I changed the Evan canister and purge solenoid.
I don't know when I did mine I went with the "standard" brand I think is what it was called ordered from rock auto
 

Forum statistics

Threads
132,202
Posts
1,863,979
Members
96,732
Latest member
DavidJ
Top