Volvo Troubleshooting Questions? Ask a Mechanic for Answers ASAP
welcome,700 code just tells you there is a problem in the transmission. the 705 code is the transmission range switch which tells the computer which gear the transmission is in. the 420 is catalytic converter is below effiency. the shift range switch may need replaced. the cat may also need replaced. but I would have a scan done with a tool with volvo software sometimes using a generic tool can lead down the wrong path.
this is information already known from codes answer unaccepable