Well, I started off easy. I replaced the gas cap with a new one and thought it was fixed till the SES light came back on. I also brought a Actron Scanner for $106.95 which I need to keep resetting the light. Does anyone have any idea what this might be since I already did the gas cap thing. Anyone have a 03 Maxima Service Manual online or know where I can download one. I used to have one but lost it when I reformatted my computer. All and Any Help is Appreciated.

 

its a very small leak in the evap system, its usually not related to the gas cap.

youre installing the gas cap until it clicks, right?

and is the evap svc port cap on tight?

other than that, youd have to run a smoke test and locate the leak like that.

 

I know this is not an answer to your question but can't you just perform an ECU reset as per Studman's procedure to reset the light?

 

Where is the EVP SVC PORT located?

 

Anyone help?

 

its in the back kinda behind the MAF, near the bank 1 cam sensor. its the green cap thatll be on a line coming form the purge valve. it shoudl be the only green cap in the engine bay.

the light will turn on within a few miles of driving, he needs to fix the probmlem.

 

Well, The light still comes on, not every few miles though, it just comes on when it wants. I did the gas cap thing, even put in the best gas and cleaner I could find hoping that was it. Now I have no idea what to do. I have the 03 maxima Service manual downloaded and well if anyone is good with understanding it, maybe I could send it to you and then you could give me an idea of what to do.

 

ive read it... theres a LEAK.

a vapor leak in the EVAP system. you need to find the leak, and if the light is coming and going, it might be an intermittent thing (like a sticking/leaking vent valve)...

 

Where would I look for that?

 

you would connect a smoke machine to the EVAP test port and seal the system, then look for the smoke.

or you can pressurize it and listen for the leak if its quiet around. do NOT exceed 0.6psi

you can also pull a vacuum on it and listen.

 

EVAP control valve that takes the gas fumes from your gas tank and releases them back into the engine. The dealership will charge around $100 to replace ($20 part, but $80 labor).

 

that would be the purge valve

 

Sorry to bring this one up from the dead, but it was all I could find using a google search.

I'm having exactly the same problem with the P1456 code on our '02. After resetting the ECU, the MIL will usually come back on withing a few miles of driving. Using the Auterra Dyno Scan software on my laptop, it reads "Fuel Tank Temperature Circuit Manfunction" and says nothing about the EVAP system.

I know very little about the EVAP system. Is there a picture or diagram (out of the service manual maybe) that illustrates which components are related to the EVAP system and what they do?

HCT67: Did you ever come to a conclusion with this? What did you have to repair/replace?

Thanks for your help!

 

This is also the only thread I could find searching... I have this same code. I had it reset and since driven about 300 miles in about a week's time. But, now the light has come back on. Is this evap leak dangerous? I'm not going to be driving my car much over the next three months (as I am going back to school) It will maybe get driven 2x.

I'll get my mechanic to replace the valve, if that is what you guys are pretty sure needs replacing...

 

it could be ANYthing compromising the integrity of the evap system. this isnt really something to guess at.

klinger, what was the code number you got? i dont recall there being a fuel tank temp sensor.

 

I can show you exactly what came up on my laptop. Here's a screenshot:

http://www.pages.drexel.edu/~art28/A2.JPG

Note that it refers to it as a Ford code. This usually doesn't mean anything, other than that Ford was the first to develop this code when OBD-II was coming about in the early '90s. I have found MOST codes to be generic to all vehicles.

There is also some inaccurate data. For example, it lists the MIL as occuring when the vehicle speed was 92mph but the engine speed was 2050rpm, which is impossible with the stock automatic transmission in Drive.

I don't know how seriously to take this data. It is what I have.

I still haven't resolved this issue. The MIL is still on.

Any thoughts? Is there a Fuel Tank Temp sensor? Is this an EVAP problem?

 

Also had a P1456 on my Max. Dealer used a smoke machine, and found a small leak through the charcoal canister. Replaced the canister, and all is good.

 

I have P1456 on my car recently. The rim on the gas filler is rusted so my dealer said that it is the problem. Had it replaced and I still get the same error code.

Dealer suggested running the smoke test to find the problem but wanted $230 to run the test. But dealer will deduct the cost from the initial analysis (130).

Looks like I have to run the smoke test to find the leak.

Thanks for the above poster's input.