Hey everyone. I haven't been very active on the forums lately but I'm back. And with a ugly little light that none of us like to see. The check engine light. I'll start off with the Jeep runs fine. Starts right up, idles fine, shifts fine etc. The code it's throwing is PO455 which is large EVAP leak. Possibility number 1. Defective or loose gas cap. I've checked to make sure it's tight as well as checked the o-ring and it's all good. So I don't think it's that.
Possibility 2. EVAP canister is broke. hose cracked or not connected.I've inspected the canister and surrounding hoses and can't see any cracks
3. Purge or vent solenoid defective. I'm not exactly sure what that is so it's a possibility.
4. Vaccuum leak at engine. This would be my bet. I'll explain why.
The jeep makes a high pitch whistle that comes from under the hood. I believe it's the ICAV housing gasket (which I don't believe anyone makes a gasket for.) The whistyle goes away when I apply throttle but comes back once I let off. It typically doesn't happen driving around the city but on the highway its almost certain.
And my final question is am I doing damage driving with this EVAP leak?
Any and all advice/help is greatly appreciated. I know the guys on here really know their stuff so I'm hoping for the best. Thank you.

 

Your EVAP purge solenoid is located just above the AC lines on left side of motor looking in from the front, its back by the fire wall.

start checking all lines going and coming to it..

here is a vid to show where it is.. I made this vid to show the clicking is normal, but it will give you an idea where the solenoid is at.

 

So I should hear that clicking if my engine is started? And I'd I don't does that mean the solenoid is junk?

 

Look for the solenoid to start clicking when the engine coolant temp reaches around 150*F.


Crawl under the Heep at the fuel tank. See if the steel tube from the Evap canister to the roll over valve on top of the fuel tank is all rusted out. If so, it needs to be replaced.

 

And after you check out the steel tube, shimmy towards the front of the jeep. Plastic tubing from the Evap canister meets plastic tubing from the engine underneath the driver's seat. The connection should be held together with a 3 or 4 inch length of rubber tubing. Make sure the connection is solid.