# '03 Frontier - Error Code P1491



## sbigshot (Dec 16, 2005)

I have a 2003 Frontier XE 4cyl and got a P1491 error code. Does anyone have any experience with a cause for this code and if so, a permanent fix? 

Thanx in advance!

(I do know that it has something to do with the evap/fuel system)


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## jerryp58 (Jan 6, 2005)

sbigshot said:


> I have a 2003 Frontier XE 4cyl and got a P1491 error code. Does anyone have any experience with a cause for this code and if so, a permanent fix?
> 
> Thanx in advance!
> 
> (I do know that it has something to do with the evap/fuel system)


I don't have any experience with it, but my '04 service manual has these as possible problems for 1491:

 Vacuum cut valve bypass valve
 Vacuum cut valve
 Bypass hoses for clogging
 EVAP control system pressure sensor and circuit
 EVAP canister vent control valve
 Hose between fuel tank and vacuum cut valve
clogged
 Hose between vacuum cut valve and EVAP canister
clogged
 EVAP canister
 EVAP purge port of fuel tank for clogging
 Refueling control valve
 Refueling EVAP vapor cut valve

It says the fault condition is "Vacuum cut valve bypass valve does not operate properly".

That's a lot of possibilities, but I hope this helps some.


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## sbigshot (Dec 16, 2005)

^^ Thanks for the info ... I cleared the CEL, if it keeps coming on, I guess I will have to start troubleshooting.


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