I’ve got a 99 4.0 and it’s running pretty rough. Can’t really figure out forsure what it is so I haven’t done much to fix it but first whenever I start it it always starts at a really low RPM and sputters until it climbs to a normal idle. Second when I put it in drive it feels like it wanting to take off without me giving it any gas and foot on the brake. Almost like someone is pushing my truck back and forth. Does the same thing when I’m driving just doesn’t run or feel right. I had oreillys run some codes and they said it was either my spark plugs and spark plug wires or cylinder 5 misfire. I’m hoping it’s just the spark plugs but if someone could point me in the right direction that would be great.

 

Without actual code numbers, anything else is just throwing parts at it.