Nissan Repair: Is it expensive to repair, altima, gag

Question
Altima will not stay running. Had car put on testing machine and got codes: po03, po17. Car misfiring on pins 1&4.

Answer
Alvin,

Recap your plugs.  This does not have an expense. Unless you take it to a shop and have it done.

To do yourself:
Get Chilton Manual for vehicle, look up the gap for your plugs, have a Fueler gag and set the plugs to the proper gap. Upon completion of this process see how your car responds.

Darrel