Pontiac Problems? Ask a Mechanic for Answers ASAP
good afternoon my name is ***** ***** I will assist
what motor do you have?
ok, thanks. the one thing that all the codes have in common is low fuel pressure. it is a common reason for the 300 code and all the individual cylinder miss fire codes. the 174 is a lean code which also supports not enough fuel. you need to have the fuel pressure checked to see the actual pressure versus what is needed. you may have a weak fuel pump.
not miss fire codes. yes it could be but I doubt it
why do you think it is related to the repair???
I would start by checking the fuel pressure. that will tell us a lot. once again, a vacuum leak is not the issue here unless your engine idle is abnormally high which you have not indicated