Emissions help
 

My 2000 SS threw a code at emissions today P0449.."Evaporative emissions system vent valve/solenoid circuit" What do i need to replace and where is it on the engine..Thanks

Does anyone have any suggestions? I was surprised to not find an answer already posted.

Could be that the valve itself has gone bad, or some of the wiring for it.

Had the same problem on my 93 F150. It was the electronic solenoid on top of the EGR that opens and closes it.

P0445 + p0449
 

2 codes came up on my 2001.
P0445 happened. I took off the small EVAP thing under car up by gas cap and installed new one from Auto Parts store. Bought new GAS CAP too. That was a NO NO !! The p0445 came back so I replaced the EVAP thing on the front of the engine. Now! I got the P0449 code. Hmm picked up code reader/rest. Cleared and still P0449. went to GM $37.00. GAS CAP. Just replace gas cap first thing. Let me know if ya need more specifics https://montecarloforum.com/forum/im...c/progress.gif

:eek: :soapbox:

evaporative emissions vent valve soleniod
 

Where is it located. I thought ur post said up by the gas cap. Is this were it is located???

Yes , It is under by the rear wheel behind the body just under gas cap... jack up car left rear u can see it plan as day with a small light!! by the filler tube for gas..

I have a 06 Monte Carlo lt 3.5 check eng light came on I replace the gas and the vent valve solenoid drove it for a couple days it still on... on the valve solenoid wire harness it reads both positive n negative. What else can be wrong?

PO300
PO403
PO405
PO446 ✴︎ ⬅︎ ⬅︎ ⬅︎

All these Codes were triggered by a faulty FUEL TANK PRESSURE SENSOR!

Wait for the Low Fuel Warning before attempting to DIY.
Start engine.
Pull FUEL PUMP Relay ... Let Engine stall to relieve pressure in system.
Remove GROUND Wire from Battery.
With car Raised and SAFETY STANDS securely in place.

Support Tank with Jack.

(I made a "Jig" to attach to the Jack. Sawed the square bottom off from Milk Crate. Drilled holes through Hockey Puck. Mounted Puck to center of Milk Crate with Heavy Duty Zip Ties. Affixed carpet to other side of Milk Crate bottom for padding.)

Lower tank enough to access Sensor atop Fuel Pump.
Unfasten Pigtail from Sensor.
Unclip and Remove Sensor ••• Straight-up.
DO NOT BREAK THE END OF SENSOR OFF INSIDE PUMP!!!

If you need a Charcoal Canister do it when you replace Sensor.

Removing Relay to releive Pressure throws a Code which may require a MIL Light reset.