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Evaporative Emission System?

28K views 14 replies 10 participants last post by  Gabby123 
#1 ·
Hello-

I am having the engine light on, pulled the code and this is what it gave me. I have no idea where to start to fix the problem.

Did anyone have this before? Thanks! Text Font Line Number Screenshot
 
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#4 ·
There is a small valve on top of the intake manifold held on with 2 10mm bolts, that has a vacuum line Teed off of it. This valve is used to control the EVAP system and is a common failure point on a handful of Ford Vehicles. I have replaced the one in my Dad's explorer already, and the one in my Wife's car is being temperamental and will likely need to be replaced here soon. The valve itself is only like $30, i'm just being lazy.

Do some research and diagnosing the evap valve and see where that leads you.
 
#7 ·
I had that code a couple months ago, along with a couple other symptoms... occasional hard starting after fuel fill-up, occasional stumble at idle. I cleared the code and it came back after a few days. Like Voltwings said above, mine was the evap canister control valve on top of the engine. Got mine from Rock Auto for something like 25 bucks, it took less time to change it than it's taking me to write this post. Super easy.

Do a little research online, you can actually test the valve with no tools: Disconnect the electrical connector and the vacuum line from the valve, then start the car and put your finger over the port where the vacuum line attaches. If you can feel engine vacuum pulling on your finger, the valve is bad, since with no electrical current (the connector is disconnected) the valve is supposed to be sealed closed (no vacuum to the hose).
 
#14 ·
Do a little research online, you can actually test the valve with no tools: Disconnect the electrical connector and the vacuum line from the valve, then start the car and put your finger over the port where the vacuum line attaches. If you can feel engine vacuum pulling on your finger, the valve is bad, since with no electrical current (the connector is disconnected) the valve is supposed to be sealed closed (no vacuum to the hose).
Did this test today and confirmed that the purge valve is leaking. New one is on order!
 
#9 ·
Hey Guys!
Just bought my 2012 Mustang V6 Premium and about 3-4 weeks later I got this code.
Got the code "P0456" pulled at autozone, I disconnected the battery and code was gone for 2-3 days and then came back so I figured its probably not gas inlet. I went to my local dealership and the guy in the service department insisted on the evap canister control valve not being covered under emissions warranty and showed me someone else on their system who didn't get that code covered under emissions warranty. Wanted $69 dollars for Diagnosis, yeah right...
Any suggestions? Should I buy the evap canister control valve and replace it?
 
#10 ·
You mean if your under 5 years/50,000 mile power train warranty?
 
#13 · (Edited)
Just got the CEL and this code this morning too (one stored, one pending, just like the OP). I cleared it, but now with key in IGN (not START/RUN), the CEL will flash a handful of times and sometimes stay off, sometimes stay on. I assume this is because the problem is intermittent or I haven't had enough warmup cycles to clear it from PCM memory? The code reader reports zero codes now.

I visually checked the evap canister purge valve and removed/reseated the connector to see if that helps when I start the car in the AM.

I also have the JLT catch can replacing the passenger side PCV hose. If the catch can is creating a vacuum leak, could this throw the code?

Given that the car has 81k miles on it, I might just go ahead and replace the evap canister control valve since it's easy and cheap. Is this the part sitting on top of the intake mainfold?
 
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