1999 tahoe with check engine light

[dream]

my husband recently had the fuel injectors cleaned at a local quick lube. the following day the check engine light came on. he took it back to the lube joint and they told him this usually happens because of the system taking in more air and it would go away after a few starts or that he could try to disconnect the battery to reset the system. we tried disconnecting the battery but this had no affect. we made a long trip (3000 miles) and along the trip the light did turn off during a good portion of the trip, however it did turn on on the trip home. he took the truck to the chevy dealer and they registered the following report:
72163 P0171 Bank 1 Lean, Blcok Learn + 20 % P0174 Bank 2 Lean, Block Learn 20 % P0420 Cat Converter low efficency 11 road test highway fuel pressure dropping off on hills, needs fuel pump $303.86 + filter $21 + labor 0350 needs cat converter $687.75 + labor 0200

i am mechanically declined but this seems so coincidental that the light came on after the injector service. could use a professional opinion on this situation as well as direction on what the next step should be...are the prices in line if i need to actually get new parts...if not, where should i look to obtain the parts.
much thanks...