While driving on the highway, suddenly the CEL started flashing and the truck started msifiring, I got off the highway and retrieved a P0171, P0300, P0301 , P0304. I shut it off and waited for a few minutes, I re-started it and the misfire was gone along with the flashing CEL but I could feel that it is not running 100% but no major misfire, I drove home (about 40 miles) and as soon as I got off the exit it started misfiring again, Since I did not have time to diagnose it correctly I took a guess and ordered a coil (as it fires 1&4 , all 4 plugs and wires are new) on the initial startup after the coil replacement it was fine but then started to misfire again (P0300 , 0301, 0304) . I turned it off and waited, misfire was gone. I then parked it. Would it be fair to assume that the 1&4 cylinders are lacking fuel (lean code)? as the ignition delivery is fine and I would assume there is no mechanical fault as the misfire is intermittent

  • Welcome to Motor Vehicle Maintenance & Repair! Have you read the plugs on 1 & 4? If it is a lean fire condition, these plugs would be very tan in color. If it's the ignition system and the injectors are still firing, they'd look fuel soaked. You'd need to check them after you shut the engine down from when it's misfiring to see anything (and then it still might be difficult). If you restart the engine after you shut it down, but before you check the plugs, the evidence could very well be burnt away. Nov 15, 2018 at 19:23

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It also might be the crank sensor because I have a 02 Jeep grand Cherokee Laredo and I was having the same problem and I put crank sensor in and it fixed it

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