Getting codes P0340, PO430, and PO420 on the GX.

Any idea's on what this is going to cost me?

Its a 2003 GX with 111,000 miles. Picked it up friday and the lights came on 40 miles into the trip from the dealer. Go figure....Should I ask for half of it to be paid? I thought it was illegal to sell a car with Cat problems???

 

Also the CEL went away for a while randomely but has since come back/.

 

These codes are as follows
P340 - Camshaft Postion Sensor A Circuit
Solution - Check the Battery voltage, if there is severe drop this is the first Warning comes up on the ECM. Maybe it is high time to replace.

P0420 & P0430 - Catalyst System Efficiency below Threshold Bank 1 & Bank 2.
Solution - Either there is a Leakage in the Exhaust System or the Oxygen Sensors are fired. Do a visual inspection below under chassis right from the manifold till the exhaust tip end with a bright light and checks for leaks and have them fixed, if exhaust leaks found fix it with Permatex 1000 Degree Plus Exhaust Repair Kit, they are really good.

cheer, hope this helps