P0446

Tiny
DELPHN.C.
  • MEMBER
  • 2003 PONTIAC GRAND PRIX
  • 3.1L
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 163,000 MILES
Replaced evap. Vent valve solenoid and ECM. And gas cap. Checked with a evap smoker. Still a problem. Question is, is there a Can bus module on this car.
Wednesday, April 20th, 2016 AT 3:27 PM

9 Replies

Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
It's a blocked vent line someplace in system it needs to be smoke tested in order to fix this.
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Wednesday, April 20th, 2016 AT 3:38 PM
Tiny
DELPHN.C.
  • MEMBER
  • 3 POSTS
I have already smoke tested. Cleared the vent line. Pulled down gas tank to check all lines and conections. CheckEd evap filter. Made sure it was clear.
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Wednesday, April 20th, 2016 AT 3:45 PM
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
How about vent line to tank?Is the vent link kinked or pinched? Does solenoid operate
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Wednesday, April 20th, 2016 AT 4:22 PM
Tiny
DELPHN.C.
  • MEMBER
  • 3 POSTS
Vent line to tank is open. Replaced solenoid and checked it.
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Wednesday, April 20th, 2016 AT 4:25 PM
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
From the factory the evap system is checked with 3 psi air pressure. Try applying that much and see if one of the hoses isn't opening and maybe soft and collapsing. Other than that I don't know what to tell you, especially since you smoke tested it and replace solenoid. Unless it's a connection or pcm problem which you can check with an ohm meter.
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Thursday, April 21st, 2016 AT 6:03 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 43,072 POSTS
Here is an article with video to show you how to fix it

https://www.2carpros.com/articles/evap-system-code-repair

Let me know what you find

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Thursday, April 21st, 2016 AT 6:55 PM
Tiny
ROBERT MANN
  • MEMBER
  • 2 POSTS
I had the same problem with a 2001 chev impala to fix it I had put a little form a gasket on the evap lines at the engine the small o ring inside evap line no good put form gasket on inside line with Q tip and on pipe now no more p0446 done to a couple of autos work good for all of them.
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Tuesday, August 30th, 2016 AT 8:55 PM
Tiny
ROBERT MANN
  • MEMBER
  • 2 POSTS
THE O RING DOES NOT SEAL AS TIGHT AS NEW SO TRY FORM A GASKET TO SEAL THE EVAP LINES AT INTAKE SHOULD HELP FOR THAT CODE P0446
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Tuesday, August 30th, 2016 AT 9:00 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 43,072 POSTS
You can try a new line or a larger is diameter O ring. The system must be air tight.
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Wednesday, August 31st, 2016 AT 9:29 PM

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