MJ14

Hello everyone, I am new to the forum and I am hoping there is someone here who can help me out! I just recently purchased an 04 F-150 2wd with the 4.6L V8 with 200,000 miles. I have put around 1,000 miles on it since I purchased it a few weeks ago and it was running great.

A few days ago on the interstate it started missing firing like crazy at 80 mph. I got it into town about 5 miles down the road and it was shaking pretty badly at idle. I took it and got the codes checked and it said cylinder 1, 3, and 8 misfire. So I purchased new plugs and coils and I installed them today. While we worked on it, we left the battery cables off of the battery. So when I started the truck up the light was gone but the truck was still shaking pretty bad. I took it for a test drive and it shakes the whole time it is driving but it won't throw another code. So I unplugged the MAF just to see if anything changed and drove it around the block and nothing changed with it. It threw a wrench light on while I drove it with the MAF unplugged, and as soon as I plugged it back in the light went right out.

I also put some fuel injector cleaner in with my gas because I just filled the tank at a place I don't ever get gas from. Anyways, I am not sure what my next step is. No light will come on now and when I watch it on the scanner everything looks fine, but it shakes anywhere I go now. Though it doesn't seem to lack power like it did the other day when it was misfiring. What should my next step be?

Martian

You need to do a relearn because the battery was off so long and you should probably drop your spare tire to get eyes on your FPDM mounted on the frame rail... at that mileage if it's never been replaced before it's probably a swell idea to do it now