code PO446
 

I have a 2004 XG350L with 40,000 miles. I keep getting code PO466 Evaporative emission control system vent control circuit. It comes on for a couple days then goes off and then reappears again. What do I look for to solve this ongoing problem. Please help Rick

RE: code PO446
 

[ul][*]First of all, make sure you tighten your gas cap when you fill it. A loose or leaking gas cap will generate this code.[*]A small leak in any of the EVAP hoses or fuel tank hoses[*]A small leak in the purge valve or vent valve[*]The EVAP Canister may be leaking[/ul] Possible Solutions First, using a scan tool activate the vent solenoid, sealing the system. Then monitor the fuel tank pressure (FTP) sensor. If the system is sealing properly, the number will stay consistent. If is isn't, the pressure sensor will show that as well. If the system slowly leaks, use a smoke machine and watch for smoke exiting the system at any EVAP component. Any where there is smoke exiting the system, that is the faulty component. Do not pressurize the EVAP system with air pressure. Doing so can damage the purge and vent solenoids in the system.

RE: code PO446
 

Thant you for the quick reply.I do not have a smoke machine So I am guessing I must take my car to a dealer to have this test done. I do have a scan tool and can read and reset trouble codes only. should I buy a new gas cap befor going to te dealer.? Rick

RE: code PO446
 

A new gas cap would be cheaper. Go to Walmart and get a locking cap for $10.

RE: code PO446
 

Thank you for the fast replies. I will try a new gas cap and see if the problem goes away. Thanks again for your help. Rick

RE: code PO446
 

Hold on. Before you go out and but new parts try making sure the gas cap it tight first. Many times that code comes onjust because the cap is loose. The owners manual says you must make sure the cap clicks at least 3 times when replacing the cap after filling up. If that doesn't work, then consider buying a new cap or get your cap tested at a garage. Testing the gas cap is part of the normal emissions testing.

RE: code PO446
 

I will stop at the emmision station on the way to work and see if they will test the cap. Thank you,Rick

Sounds like my problem
 

How did it turn out for you? How did you finally resolve the problem?

I have 2001 XG300L. TCS/ABS light is always on. I contacted manufacturer who makes OTC 3208 scan tool. They said only Azera is US Emission compliant, not XG. Does it sound right? I like to buy their OTC 3208 but if it does't work then there is no point.

Any comment will be greatly appreciated. My XG engine and transmission are of no problem, drives very quietly and smoothly. Only the electronics is not so good. Thank you all.