My car has code P0357?

2004 MERCURY GRAND MARQUIS
246,509 MILES • 4.6L • V8 • 2WD • AUTOMATIC
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PETPARENT
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  • 15 POSTS
My car has code P0357. I repaired it before by putting a new spark plug and a new spark plug insert into the cylinder head. It continues to give me the code even after removing the old plug and replacing it. I also removed a piece of rubber from the spark plug chamber. I thought that would solve my problem. Service Manuel said it was a circuit malfunction to check the circuit.
Dec 22, 2024 at 11:48 PM
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STRAILER
  • ✓Experienced Mechanic
  • 55,051 POSTS
It is common for the ignition coils to go out on these engines, I would replace the coil with a new unit.

A P0357 code indicates an issue with the Ignition Coil "G" Primary/Secondary Circuit.

This video will show you how:

https://www.youtube.com/watch?v=e68QXyBAiZo

Happy holidays!
Dec 23, 2024 at 5:37 AM
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PETPARENT
  • MEMBER
  • 15 POSTS
Should I check the circuit from the wiring harness for the engine and possibly look for short circuits or other problems in the ignition coil connector?
Dec 25, 2024 at 4:41 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,051 POSTS
Yes, you can inspect the wiring and connector but most of the time it will be the ignition coil.
Dec 26, 2024 at 3:30 AM
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PETPARENT
  • MEMBER
  • 15 POSTS
Yes I will inspect the wiring and check it out with my test light and multimeter.coil was last change and check almost 2 years ago.
Dec 30, 2024 at 12:29 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,051 POSTS
Okay, also make sure the spark plug is not cracked, this may cause the issue as well.
Dec 30, 2024 at 1:32 AM
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