Engine Misfire

[DeliveryDave]

I have a 2019 New Body style 1500 5.7 2wd
94k miles
Last week I had a Check Engine for Cylinder 4 misfire. I replaced the plugs first on cylinder 4, the shaking was pretty bad, then replaced the coil pack and the shaking calmed down a bit after a can of SeaFoam and 20 mile drive. The shaking has came back. Took it to a shop the gentleman said cylinder 4&6 were misfiring and recommend the ECM be replaced. Called dealer they said sounded life a cylinder and lifter issue. Was gonna trade it in tomorrow since no check engine light is on, but the shaking has began to pick back up. Any idea what could be causing that? Maybe just replace all plugs and coil pack?

 

[Hagar1]

I have a 2019 New Body style 1500 5.7 2wd
94k miles
Last week I had a Check Engine for Cylinder 4 misfire. I replaced the plugs first on cylinder 4, the shaking was pretty bad, then replaced the coil pack and the shaking calmed down a bit after a can of SeaFoam and 20 mile drive. The shaking has came back. Took it to a shop the gentleman said cylinder 4&6 were misfiring and recommend the ECM be replaced. Called dealer they said sounded life a cylinder and lifter issue. Was gonna trade it in tomorrow since no check engine light is on, but the shaking has began to pick back up. Any idea what could be causing that? Maybe just replace all plugs and coil pack?

Did you do a compression test? What were the results?