Code PO42O and PO43O ? Anyone know what they

The main problem looks like P0306 which is a missfire on #6 cylinder. P0300 means random misfire so you may have another cylinder misfiring. How old are the plugs?
P0031, P0430 and P2238 all are related to the O2 sensors on bank 1. Which is probably caused by the misfiring of the spark plugs.
I would have the spark plugs changed first. Erase all the codes and then see what happens.

this indicates the catalytic convertor isn't working at correct values , this may be due to a leak in the air intake system or the exhaust system before the cat convertor , if no leaks found i'd recommend a fuel addative that cleans the catalytic convertor as well as the engine parts , take for a longish drive (50-100) at a highish speed to get to a high engine temperature , may have to do this a couple of times and rescan for code , if still showing code will need further investigation as to which sensor may need replacing

U0100 means lost of communication with ECM/PCM
U0101 means lost of communication with TCM

this sensor is located on the side of the engine that cylinder 1 is on,assuming this is a v6 or v8.you will have to check the 02 wave form to make sure the 02 is switching properly,if it is then you will have to check the effiecency of the catalytic convertor on the same side.it may be the problem and not the convertor.

http://www.easterncatalytic.com/education/tech-tips/the-misleading-nature-of-the-po42o-code/
try this info out.

Bank 2 is at the front of the car.

http://www.easterncatalytic.com/education/tech-tips/the-misleading-nature-of-the-po42o-code/
this should help clarify the possibilities

this should help.
http://www.obd-codes.com/p0441

That code is for a catalityc converter failure( cat converter inefficiency) the converter has a federal emission control warranty for 8yrs/80,000 miles, contact the toyota dealer if it is still within to get it replaced at no charge.

Is it a water leak or an oil leak?