Q: PO304 w/ check engine light on all the time & stabilitrac & traction control turns off when at idle. Back on when moving again.

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I have a misfire in cylinder 4. I reset code after trying these things one at a time and it would throw same code again in about 30 seconds. I have put new plug. Swapped cylinder 4 coil pack with cylinder 2. Swapped plug wires same way and Swapped fuel injectors same way. The truck is down some on power. Fuel economy is way down and sometimes there is a shake at idle. No rhyme or reason to the shake, it just happens occasionally. Although it is pretty seldom that it shakes at all. When it shakes, I can feel it through acceleration until I get above 35 or 45 then it is smooth again. Also, I don't know if it is related or a separate issue, but when I come to a stop light or spot where truck returns to idle, the stabilitrack off and service traction control light starts flashing along with dinging sound. The sound stops after 2 sets of 3 dings, but the light stays on until I start moving again then all seems normal until I return to idle. This is every time I return to idle. Please help

My car has 68000 miles.
My car has an automatic transmission.

Hi there. Have you had a compression test performed? This sounds like it could be a mechanical issue plaguing your truck. This could be a stuck lifter, weak/broken valve spring, worn cam lobe, etc. I would do a compression check on the engine and, if needed, a cylinder leak down test. Best case scenario would be carbon build up on the valves in that cylinder and worst case could be a physical failure of the internal engine components. I suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a check engine light inspection.

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