wifes 2000 ls

here goes guys. my wife has a 2000 ls v8 shes had since it had 86,xxx mi. at 94,xxx mi it started missing took it to ford dealer as i had never been around one. ford replace #2&3 coils. rangood until 105,xxx mi. then it started the misfiring again. i put my small code reader on it. this time it gave me codes po 301,303,305,307plus po430 which i figured was caused from raw gas because of misfire. After joining this forum and reading all i could i installed new valve cover gaskets, i believe this had been done as no sign of oil in plug wells. put in new boush +2 plugs and replace the 6 coils that had not been replaced. took it out after about 5 mi. cel came on.got it home rescanned it gave me a po303,307 and pending 308. pulled out maf sensor cleaned it. another mech checked it said it was maf sensor problem. replaced it , ran good for about 5 mi cel on gave me a po307,pending308. unless its a fuel problem im out of ideas. any help would be apprec.

Welcome to the forum!

It's too bad that you put Bosch Platinum +2 plugs in. It seems that many modern cars don't function well with these 'specialty' plugs. I did try NGK Iridium plugs when I had my 2004 LS V8 with decent results, although I didn't notice a performance difference.

Since the coils and plugs are not too bad to get to on the V8, I'd suggest you move the coils that are currently on 7 and 8 to other cylinders and see if the codes follow the coils. If not, then try moving the coils back and the plugs to different cylinders to see if the problem now follows the plugs. If it does, carefully check the gap of the spark plugs and see if the gap on 7 and 8 are significantly different from spec or the other plugs.

-Rod