Ok. About 2 months ago I made a 400omi trip. On our way back I noticed that my engine seemed to have a couple misses. Later I found out number 5 and 8 cylinder misfire. I went ahead and changed the plugs and everything went along smooth. A couple days ago it started again. Number 8 this time. So I pulled the plug and it was burnt out. Just to make sure it wasn't the coil we tested the spark and I even swapped the coil with another one. Just to be safe I put in some more plugs. It stopped the misfire but now my engine is just a little bit jumpy but not kicking up any errors.
So it just so happens that my apartments handyman used to be a mechanic. He asked if I had checked the fuel filter. I was like no. He said it could be an injection issue. I remember on my 98 Deville I had a similar problem after I did a tuneup and I changed the fuel filter and it was like magic. So this morning I head out to Autozone. Come to find out the fuel pump and filter are one unit. Atleast thats what the guy told me.
My question is do I have to change the pump with the filter. If the pump is still working why replace a perfectly good pump?
Also he said maybe it's not getting enough air and the mass air flow sensor could be bad. The only code that kicked up was P0308 I think that's what it was and it showed number 8 misfire. Wouldn't there be a code for a bad sensor? The reader I have has a live data feed and everything seemed to be running fine.
I'm really trying to avoid a dealer if at all possible. I just put in to resign my job later this month so money is gonna be tight til I leave the country. I really don't need this right now. Any help or insight would really be great.