Alright... After throwing the code PO496 awhile ago and no signs of it returning after about 2 months i thought i was alright...

I scanned my car with my OBD2 scanner and it shows that all of the systems are okay except the Evap System... I've tried a few times in the past week to see if it when through all of its parameters and it still hasn't. I was told that it may be because the car is garaged in a heated garage at night and that it doesn't get cold enough (the tech i talked to said that happens sometimes with cars that have a *natural pressure* evap system) I wasn't sure if that is the case or not but Does anybody know what kind of evap systems our car has?
Any info on this would be appreciated thanks.
Oh yeah... and no codes in the past few weeks and that goes for pending codes also

bump

 

The Fuel tank pressure sensor is seeing vac when not in a purge situation. A few things I have seen cause this a leaking purge valve or installed backward, a bad fuel tank pressure sensor or plugging in the Boost solnoid connector into the purge valve.

 

i've been throwing the P0449 & P0455 codes. i've checked both 02 sensors, gas cap is snug, and i'm not sure where the purge valve and solenoids are located. is there a GM tech on css.net that can get a diagram of the system?

 

I guess i'll hafta do what i really didn't wanna do...
Set up an appointment at the stupid ass dealership that ***** everything up... I wish there was a decent dealership around here that actually knows **** about the cobalts

 

Yea good idea, let the so called profesinals handle it lol.

 

lol yeah then when the drive my car they'll ******* beat the **** out of it... and when the take **** apart, not put it back correctly... been there

 

GM dealers are the worst! Never had one good experence at a GM dealer. I've been to 3 in the last 7 years with my Cavalier and the Cobalt and there crazy stories with all of them.

 

ha.. i've had bad luck at the only 2 dealerships i went to for warranty work.. GM and Jeep maybe if they hired ADULTS to do the work and not dumb lil ***** that arent certifed maybe i'd feel more confident they've got kids there with no education on cars (it seems) and i don't want them anywhere near my car

 

The highlighted part in this pic is the purge solenoid valve.



The highlighed in this pic is the evap canister and the can's vent valve.



The only routing of the evap system i can come up with is this crazy pic from SI.

Hope it helps

 

oh wow, this will help out a lot! you da freakin man! now i know what the hell i'm looking for.

 

yo fr33k, your the ****! Way to pull through for a cobaltss member!
+rep

 

glad to help out. If I can help, I'll try.

 

Thanks man thats gonna help out alot

 

Oh, I forgot to mention that item number 26 in the second pic is..................

THE EVIL MONKEY IN THE TRUNK!!!!!!!!!!!!

lol

That's the knocking noise most balts have. The ones that knocks between 3 to 5 times real fast then quits.

 

I have the same problem...

Started out a few nights ago, I drove literally 3 miles down the street to Sunoco, filled up, went to leave the pump, and the b*tch wouldn't start...got it to start, revved up to bout 3 grand, came back down to under 750 and shut off...did this bout 3 times...got it started after letting it sit bout 20-25 min...hooked it up to the scanner, it was reading lean...cleared the code, CEL came back on...cleaned off the mass air flow sensor and hooked it up to a different scanner and the EVAP code came up and wasn't reading that before....cleared both codes again, seemed to run fine...sat at a redlight for not even a minute, and car seemed to idle funny again, but no CEL...it doesn't always do this...now what do I do

 

God I have EVAP problems! I've been a Hyundai Tech for 4 years now and they are notorous for EVAP codes.

CobaltSSChick, that sometimes happens if your purge valve sticks open. What codes did you through?

 

dude pulled through! +rep if i could! cleared my codes last night and now it's back on. gonna check to see exactly what i got. i did notice after filling up at the pump when i put the gas cap on it actually has a lil wiggle to it...not sure if it always has or not.

 

This time of year is horendice for water condensating in yours and their(gas station) gas tanks .
Always keep it full to stop the problem if thats what it turns out to be.

 

Sounds like the EVAP system is leaking to atmosphere when the solenoid is open. Your best bet is to take it to a dealer. The high idle and lean fuel trim is because the solenoid is open and can't pull vacuum with a broken system.

 

If you're concerned about the dealer beating the hell out of your car just insist that the Tech ride with you. Then you'll know how their treating your car. This is what I always do and I've never had a problem with my Chevy dealer. The guys seem pretty knowledgeable and if they don't give me an answer I like to hear, I take it to my own mechanic, who used to work for the dealer and is still certified.

 

I def. would but i can't since i work and go to school... i can't wait there for them...
youz may think im retarded for being **** but youz don't know what ive gone through with a jeep dealer ******* up my jeep let alone how many times it took the chevy dealer to get a speaker install right

 

I'm throwing the PO496 code as well what do you guys think is the best place to start at for fixing this problem? if it helps any when I fill up my car it will cut right back off and then I have to rev it and its fine till I have to fill it back up again.

 

Get up under the car and check the area of the gas tank that the hoses from the fuel filter run, i had been throwing that code also but i kept smelling gas. There was a fitting on the pump that had cracked, i had it repaired under recall.

 

I've never smelled gas, I wonder if it is a solenoid somewhere, but I dont have a warranty any more so i'm screwed if i take it to the stealership

 

Which recall? Do you mean warranty? I have a similar issue and I'm going to try replacing the sensor and if that fails then I'm gonna take it to the stealerships.