Question about 2004 Pontiac Grand Prix

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P0544 Code and problems with my Mechanics!

I took my car (2004 Pontiac grand prix) into a shop because I had a P0455 code. I had already had my gas cap checked and they said it was fine. they did a smoke test and told me that it was the a "gross leak in the evap emission canister purge solenoid" so I paid them $100 to fix it. Three days later the light came on again so i took it back and they did another smoke test and told me it was the same thing. So I said "I thought you fixed it?" and they said they fixed the one in the back. now the one in the front needs fixing. So I have two questions. 1) are they full of crap and just giving me the run around? 2) where is it "front" purge solenoid located, what does it look like (link a website with a picture) and can I fix it myself (without tearing the car apart)?

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There is no code P0544 , maybe you mean P0455 ?
The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge solenoid valve OPEN and the EVAP canister vent solenoid valve CLOSED . This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the control module commands the EVAP canister purge solenoid valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. If the system is unable to achieve the calibrated vacuum level, or if the vacuum level decreases too rapidly, this DTC sets.

It's called EVAP purge solenoid , the front one . An your Mechanic is probably not full of it . You need to know how the system works . If the computer set's a code for that system , it will not test it again till it's fixed an sometime other problems come up . After he fixed the first problem he should have told you that after a day or two or a couple of key cycles , starting the car cold till warm an a cold start again , sitting over night , 8 hours . Then the computer will retest the system . An other codes may set . Before putting blame , you should have to read about OBD 2 emissions , before being able to have a vehicle .

Posted on Mar 20, 2017


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Posted on Jan 02, 2017

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SOURCE: Check Engine Light - Code numbers P1486 & P0455

Found on my jeep that the high quality vac line to the evap bottle had split on the under side.

Posted on Sep 03, 2008

  • 275 Answers

SOURCE: 2004 Pontiac Grand Prix Evaporative Canister

you should be able to fix it look for a can near the fuel tank that has vacuum hoses coming out of it and you should be able to just buy the bad solenoid

Posted on Nov 03, 2008

  • 104 Answers

SOURCE: p0441

i would have the front vacuume switching vavle checked

Posted on Apr 18, 2009

  • 78010 Answers

SOURCE: code p0455 evap emission (large)

have the gas cap tested or just replace it, then disconnect the battery for 5 minutes to reset the code, then drive it for a few miles and see if problem comes back, if it does a trip to the dealer is in order, as this may be covered by your emission warranty which is good for 70,000 miles.

Posted on May 26, 2009

  • 3854 Answers

SOURCE: p0455 comes back on ,we try to fix it

The EVAP control sytem is checked by the ECM upon the first start of the day when the engine is cool and will trigger the DTC code P0445. If you have a vacuum line leak when it's cold and seals it self when it warms up then the code will stay there. After warming up the car reset the ECM to clear any DTC codes and see if any MILL shows up. IF not then there is a leak only when the system is cold so your going to have to try to do a smoke test when the system is cold.
The other thing is to check all the vacuum lines and fittings around the canister and fuel tank for any lose clamps ECT.
Good luck and keep me posted. Be glad to help you 

Posted on Jun 01, 2009

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Code P0455 engine light on

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1 Answer

Does the check engine light come on in a 2003 grand prix if the gas cap is not on tight enough? Mine came on right after I got gas and I am hoping this is the case.

Yes, if the gas cap is not on tight enough or if you took the cap off with the engine running, this could very well be the problem. It will usually set one or more of the following fault codes: P0441, P0442, P0455, or P0456. I usually do not recommend getting the "free" scanning done at the local parts dealer, but this is one case where I would actually recommend it. Have them scan your OBD system. If one of the codes above are present, just ask them to clear the codes for you. Make sure your fuel cap is tight and see if the light comes back on (if it does, then you will need to diagnose to find out why). If there are any codes other than those listed above, then you should get your vehicle diagnosed to find the cause of the code or codes.

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Why Is My Engine Light On?

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Sep 22, 2011 | 2003 Pontiac Grand Prix

1 Answer

2004 Grand Prix GT gas cap light,an engine light is on. Took it to autozone an code read po445 replaced gas cap, an light is still on. is there a time limit on light going out if i jus replaced it? Or what...

P0445 - Evaporative Emission Control System Purge Control Valve Circuit Shorted is located in the engine compartment and is most likely the root of the problem.Would check the plug and wiring going to this to verify that no plug or wiring damaged has occurred.It is quite possible the part has gone bad.

Apr 26, 2011 | 2004 Pontiac Grand Prix

1 Answer

I have a 2005 grand prix and the OBDII light stays on i have checked the gas cap and its on tight

Hi, are you saying the trouble code is P0455, or have you not scanned the car? If you have not scanned the car, please get a free scan at you local parts chain and send us the codes.
If you have P0455, check the EVAP hose from the fuel tank to the charcoal cannister for leaks. Inspect the cannister and the hose to the purge valve. Make sure the purge valve is not stuck open.
Let me know if you have questions, and thanks for using FixYa.

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Did u have engine codes scanned? If not, have it done, as it may indicate the problem. Let me know. (most parts stores will scan for codes free) .

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i think it sounds like a MAP sensor... try it if u havent figured it out already yet...,868181/vehicleId,2915702/initialAction,partProductDetail/store,713/partType,00127/shopping/partProductDetail.htm

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