I posted a thread about a code that I pulled when my CEL came on the other day. It was #02 15 which I found out is EVAP Vent Control Valve. I reset the computer and it didn't come back for a couple of days. Well, it came back yesterday but with another code as well #07 04, EVAP control system pressure sensor. So since there is a new code I figured that I would bring this up again for some input and advise.
Well, am I doing more harm to the car by driving with these problems unresolved? I have to admit that I have no idea what the EVAP system does and how expensive it is to diagnose/fix.
Somebody else told me to pull out the canister and check for clogs but I cant seem to locate it.

 

Prior to the 1970s, most cars vented their gas tanks directly to the atmosphere. This contributed to the smog problem in built-up areas where there were many cars. Fuel vapors are not healthy to breathe by themselves, of course, but they can also combine with other pollutants to form nasty by-products.The job of the EVAP system is to capture gasoline vapors evaporating from the fuel tank and burn them up in the engine, so these vapors don't go directly into the atmosphere.

The Maxima's EVAP system has around a dozen different components. There is the fuel tank itself, a charcoal cannister to trap vapors, vent control valve, purge valve, purge control valve, pressure sensor, hoses etc. These components form a pressure sealed system. To make sure the EVAP system is working correctly, the ECM performs diagnostic routines from time to time. These routines are called monitors.

The reason your codes did not come back right away after resetting your ECM is that the monitor to detect that fault had not been run yet. When it did run, the light came on because the fault was still present.

You are not likely to harm your engine if you have a flaw in your EVAP system, unless you have some sort of gross vacuum leak. The most likely thing that will happen is that gasoline vapors will escape into the atmosphere. Your MIL will continue to come on,and that may prevent you from passing inspection, depending on where you live.

Diagnosing the EVAP system is not that difficult. If you are comfortable doing your own work, you can follow the procedures in the Factory Service Manual to isolate the trouble and fix it. The most common problems are the charcoal cannister, hoses or valves get clogged up, your gas cap is loose or leaking, or you have a bad hose connection somewhere.

 

Thanks man. I checked the gas cap and it is on tight. I may have to take it to my mechanic and get it tested I guess. I was hoping somebody else had to fix this and could let me know how much it costs for some of those parts to be installed. I guess this isn't a common problem on our maxes though. Thanks for the info.

 

I've had a cel on my 96 max for a few months and it won't go away. It's for the evap solenoid. I plan on testing it to see if it needs to be replaced but hadn't had a chance to. I have the Chiltons manual and it is very descriptive.

Oh and I'm getting 20mpg in the city and 290miles to the tank. When I first bought the car 2 years ago, I was getting no less than 330mile/tanks.
-Paul

 

i got same probs, and geting worse gas mileage then before. i'm getting a code for 3-way canistor? any info on this? easy to change? could it be something else liek a vaccum hose being hooked up wrong? cause it was fine until i swaped for a new motor. i use my old evap systems as donor car was an auto and it was alittle different from 5spd. an info on this? thanks

-rafal

 

Eff that stupid code. I had it for a few months and will be getting to it shortly (since inspection is coming up.) Anyone heard of trying to run it through a "dry cycle?"

 

Well it looks like this EVAP problem messed up my gas mileage too. I went from 24-25 mostly highway to 21. I was going to wait until after the holidays to get it fixed but it might make more sense to get it fixed sooner now.
Anybody know how these codes can affect gas mileage? The car seems to run the same as it did before.

 

same here. anyone?
-Paul

 

Yeah well try having your cel light on since March. I keep getting code 0903 Evap canister vent control valve. I have taken it to numerous shops including Nissan and no one can fix the problem, let alone figure out what is causing that code to come on. The repairs I have to supposidley correct this problem are to numerous to type. I have had a whole new evap system and a ecu replaced. Anyone have any thoughts on this? Or have any of you had and correctly fixed this problem?

 

Yeah I have 08 07. Ive pulled both the solenoids and no such luck so I guess its on to the canister. Damn this EVAP crap.