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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Pontiac Technician
Category: Pontiac
Satisfied Customers: 2375
Experience:  GM Grand Master Technician 2007. 14 years experience.
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Code p0455, replaced gas cap and vent valve both OE and

Customer Question

code p0455, replaced gas cap and vent valve both OE and still the same thing
JA: Has the vehicle turned into a gas hog? And how does it start -- same as usual?
Customer: everything seems to be the same
JA: What is the model/year of your Pontiac?
Customer: 05 G6
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: yes and ive replaced gas cap and vent valve
JA: Anything else you think the mechanic should know?
Customer: i think thats it
Submitted: 8 months ago.
Category: Pontiac
Expert:  Ryan Schott replied 8 months ago.

Is your fuel gauge working correctly, these sometimes had a problem with the level sensor and a line in the tank interfering which threw this code.

Customer: replied 8 months ago.
fuel gauge is workinf
Expert:  Ryan Schott replied 8 months ago.

then there is likely a leak somewhere else in the system, most of it will require smoke charging the system to isolate but you can check the purge valve so lets start there. Number 6 in this picture is the purge valve disconnect the electrical connector and the hose going to it then start the engine and see if vacuum is being pulled through the valve by putting your finger over the opening. If it is then it needs to be replaced.