Check VSC message with check engine warning light. Seemed to be running fine but now its acting sluggish like it's going to stall but doesn't. This happens while sitting still and while driving but not continuous.

Your VSC system doesn't have anything to do with your gas cap, unfortunately. You're going to either need an OBD2 Scanner to read the messages for your check engine light or take it to a mechanic/dealership to read the code and reset that light. You can also go to Autozone if memory serves and borrow a scanner to see the codes. You can pick up scanners from amazon for 10-50 USD, or about 40 USD from Autozone. Your VSC system not working means that you're not going to have optimal stability while driving until you can get the system operational again. Note that since it's Toyota Proprietary, you will not be able to read the VSC codes with the scanner, just the standard check engine codes. If your vehicle's braking system still seems to work, it could be a sensor malfunction, but I would recommend you take your vehicle to a Toyota dealership (unfortunately) to see if they can find the fault. Don't let them BS you either... http://www.greenhybrid.com/forums/f49/check-vsc-system-warning-dealer-says-normal-display-20826/index2.html

The light and the word stop should be sending you a clear message . The engine hard starting and sluggish is also sending a message and if you do not heed the message and have the fault codes read and the problem fixed then the next message may be replace the engine or gear box . The light is there --not to be an annoyance ---but to inform you that something drastic is going wrong and it needs urgent attention.

Test the fuel pressure. With gauge connected to the fuel rail turn key on, listen for pump, when it stops,turnthe key off and leave gauge connected for an hour. The original reading should been 50lbs., if it drops any more than a couple of pounds the pump is bad. The M.A.P. sensor sounds like it was another item in itself.

Whenever the check engine light comes on it also turns on the trac and the vsc, if figures the trac and vsc can not operate properly if the engine is not running correctly, when check eng light turns off the rest will also, the first thing to do is have the computer scanned, there will be stored codes, these codes will tell you where the problem is, many auto part stores will scan it and give you the codes, if you get the codes i could help you further good luck.

Battery was diconnected for 1 minute and then reconnected. All lights are off.

Definitely sounds like a fuel problem. I'd change fuel filter and check fuel pump. If pump is running it could still be partially clogged. Try a fuel rail pressure test with a knowledgeable mechanic.

Cleaning the fuel line was a good idea although it will need time to take effect. Another related problem could be clogged or stuck fuel injectors. Another thing to do is pull the spark plugs. Old or dirty spark plugs also contribute to engine sluggishness. Lastly, bring the car to an autoparts store that features free diagnostic tests. If there are any error codes stored on the car's computer, it would give you an idea where to look for any electrical problems.

sound like to me you have a clogged catalytic converter

the vsc light will come on with check eng light it disables traction control when its on when you fix or clear ck eng lite itll go off I have a 04 sienna it has bad cat conv and it comes on every couple of months I just clear it cause a cat costs like400 eventually ill fix it right.

IT LOOKS LIKE YOUR FUEL PUMP IS GOING BAD