I have a 2010 Ford explorer XLT, it has 150k miles. A few weeks ago it started to jerk while driving. Like it would do it 4 or 5 times or until I let off the gas and then it would be drive normally again. Then it started to drop in rpm's in stop and go traffic (From 500ish down to 250 then back up to 500 within 2 or 3 seconds). When I start the car up it would jump up and down in rpms for about a minute then be fine and then when the car warmed up it would randomly do the same. I thought maybe a vacuum leak but both shops I took it to said there wasn't a leak. Now today I was driving to work and a check engine light came on??
So I have a p0455 code with half a tank of gas, rpms jump up and down while sitting at idle and it jerks or lunges while driving. I need help please.