This only happens when driving 20 miles or more, check engine lt. Comes on, code reads multi misfires. A puff of smoke comes out tail pipe when this happens (grayesh). When i turn key off wait a few minutes, then restart engine is ok. Had plugs ,coil and wires changed. Happens less often but still same problem. Any help!

 

How many miles do you have on the car?Did you replace spark plug wires?If not,replace them.Had the same problem the wires alone fixed it.Costs about $255+tax at NAPA auto parts.