i have a check engine light on my 350. it says something like evaportive system emission leak. it only comes on when i fill up my gas tank. when my gas is almost empty below the second to last line it goes away. i thought it might be my gas cap and replaced it, still having the same issue. any ideas?

 

Do you tighten the cap until it clicks?

 

yes cap says click atleast 3 times.

 

What's the code you are receiving?

 

Are you leaving the car running when the cap is off? Topping off the tank after the pump stops?

 

Exact number code it is throwing, year and mileage of car might help. Telling us it is "something like" is of little help. Just sayin...

 

03 75k code is p0442

 

0442 covers a lot of possible problems....


Incorrect fuel tank vacuum relief valve

Incorrect fuel filler cap used

Fuel filler cap remains open or fails to close.

Foreign matter caught in fuel filler cap.

Leak is in line between intake manifold and
EVAP canister purge volume control solenoid
valve.

Foreign matter caught in EVAP canister vent
control valve.

EVAP canister or fuel tank leaks

EVAP purge line (pipe and rubber tube) leaks

EVAP purge line rubber tube bent

Loose or disconnected rubber tube

EVAP canister vent control valve and the circuit

EVAP canister purge volume control solenoid
valve and the circuit

Fuel tank temperature sensor

O-ring of EVAP canister vent control valve is
missing or damaged

EVAP canister is saturated with water

EVAP control system pressure sensor

Fuel level sensor and the circuit

Refueling EVAP vapor cut valve

ORVR system leaks

It all deals with the system that connects the vapor recovery between the gas tank and the intake plenum. The main parts are under the back of the car next to the tank (hidden behind the muffler) and the purge solenoid on the back passenger side corner of the plenum. I'd recommend getting a copy of the FSM and look at the EC section for your P0442 code. It has all the diagrams and locations of the pieces & parts that you'll need to look at.

See the sticky at the top of the forum for FSM info.

 

is this common with 350z? and has anyone thrown this code recently

 

It's common in the sense that it will pop up when people don't close their gas cap tightly.

 

Just get the code cleared, be careful to keep your gas cap tight and make sure you are not running your engine when the cap is off and not topping off the tank too much. The code most likely won't return, if it does, it's time to have your evap system leak tested.

 

Yeah man i just thre that code like 20 mins ago! i was told the same thing about the gas cap but i havent filled up in like almost a week so i dont think it would just now register and i always make it click more than 2 or 3 times. i got mine cleared out just hope it dont come back. mine is a 2003 with 93,000

 

Both of you guys have 03s with reasonably high mileage. It's very possible that a hose has a crack in it or a seal has started to leak or the purge solenoid has gone bad. If the code returns, that's the obvious place to start looking.

 

thats true... im waiting to see if the code returns. hopefully not. if not i will start looking into it in detail. i was told is not a big problem except for loosing gas mileage. but gas now a days isnt cheap but mostr of all i hate the light bein on!

 

oh and by the way sorry man not trying to thread jack!

 

i had this code thrown at me a couple of weeks ago, my friend who scanned it tightened my gas cap and it went away..seems stupid but alot of the times, the gas cap is the culprit

 

thanks everyone