Intermittent P0451 CEL

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Aug 2, 2011 | 08:30 AM
  #1  
I've researched the code and it's in response to EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE. Is there anyone with experience in this matter? What should I be looking for?

I cleared the code and the CEL went away for a while, now it's back. Sometimes the CEL comes on when I start the car and other times it doesn't.

I was messing with my airboxes at the dyno day this weekend, could that little tube from the splitter have come loose and cause this? Any information is appreciated.
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Aug 2, 2011 | 09:17 AM
  #2  
I googled it and it gave me this link which might help

Quote:
What does this mean?
OBD Code P0451refers to
The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the ECM increases as pressure increases. The EVAP control system pressure sensor is not used to control the engine system. It is used only for on board diagnosis.
Symptoms
Possible sumptoms of OBD code P0451
- Engine Light ON (or Service Engine Soon Warning Light)
Causes
Possible causes of OBD code P0451
- The EVAP control system pressure sensor circuit is open or shorted - Rubber hose to EVAP control system pressure is clogged, vent, kinked, disconnected or improper connection. - EVAP control system pressure sensor may be faulty - EVAP The Error code is generally activated on detection of the following conditions: - An improper voltage signal from EVAP control system pressure sensor is sent to ECM.
http://www.permoveo.ltd.uk/tabid/122...z/Default.aspx
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Mar 22, 2013 | 02:56 AM
  #3  
Sorry to dig up an old thread, but I am having this same exact problem. I have the P0451 and P0302(Cylinder 2 misfire). I had taken out and re-gapped the plugs, and still the misfire code. I am getting some new ignition wires(I still have the originals on), so hopefully that takes care of the misfire. However, I am worried about the P0451. Something weird has been happening where the gas needle would just drop to the bottom even though there is gas in the tank. I thought it was something to do with the fuel filter, so I replaced it and over time it got worse. I would have to disconnect the battery so the needle goes back to its normal position. Now, when the car is in drive and in first gear when I just let off the gas and let the car go forward on its own, it is very jerky and it shivers from underneath. It is slow and unresponsive. I dont know if the fuel pump is dying, or I got a fuel filter with a bad pressure regulator, or maybe a faulty fuel sender unit, or some sensor? Any opinions are appreciated.
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Jul 27, 2013 | 12:43 AM
  #4  
Same code here.. Cleaned out my code3 and k&n air filters last weekend and code came on yesterday.. I also thought it might have been the little hose that connects to the air box on the driver side.. I just cleared it and hopefully it doesn't come back..
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Sep 3, 2013 | 03:46 PM
  #5  
I have the same code p0451 and have p0171!!

I hope any one can help us on this
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Sep 4, 2013 | 01:01 PM
  #6  
Quote: Same code here.. Cleaned out my code3 and k&n air filters last weekend and code came on yesterday.. I also thought it might have been the little hose that connects to the air box on the driver side.. I just cleared it and hopefully it doesn't come back..
What little hose are you talking about? The my C3 CAI has some sort of breather hose but
Is not connected to anything
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