injector gone bad
I have replaced cam sensors twice and crank sensor once so far.....I had a bunch of misfire codes that could not be traced to individual holes....
Suggestion: Clear all the trouble codes. Switch fuel injector #7 to another hole (preferablly on the other bank) and see if you continue to get a po307 code. If yes, your injector is still good....
Typically, our injectors are very reliable....
You also swaped plug wires from #7 when you did the coil swap with your friend; right?
I dumped them a while back.... just hoping my wires don;t get fried as a result... my arking stoped, however...


and depending on the condition of your other injectors....yeah, it could cause the stumbling, other injectors may be dirty/on their wayout as well....