Denso is the OEM manufacturer for the ignition coil packs. In this article I tackle a P0351, P0352, P0353, P0354 code by replacing the original coil pack with a Denso 673-1307.
Bottom Line
There are tons of counterfeits on the market – expect to pay $60+ per coil for a genuine Denso Ignition coil. Anything less, be weary of what you are buying and where you are getting it from.
Replacing all the coil packs
In a previous article I discussed how started off by replacing the sockets on the harnesses on all the coil wires for only $10. I replaced all 4 coils as part of a 241k mile maintenance effort which included:
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5w/30 OIL change using Valvoline Restore and Protect
Finding the best price, prices fluctuate.
Here’s what prices were at the time of writing this article:
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AutoZone, NAPA, Oreilly, etc $100+
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Ebay – Not gonna risk it
They all had the same packaging and markings.
Photos of a Genuine Denso 673-1307 coils & packaging
Packaging
Symptoms of a Bad Ignition Coil:
A failing ignition coil will often manifest several noticeable symptoms because it can’t deliver the necessary spark to ignite the fuel-air mixture in a cylinder. Look out for:
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Check Engine Light: This is one of the most common and immediate indicators. The car’s computer will detect a misfire or ignition problem and illuminate the check engine light. It might also flash if the misfire is severe.
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Engine Misfire: This feels like a jerking, sputtering, or hesitation from the engine, especially during acceleration. It’s caused by a cylinder not firing correctly or at all.
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Rough Idling: The engine may shake, vibrate, or feel uneven when idling.
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Difficulty Starting the Engine: The car might crank but struggle to turn over, or it might take multiple attempts to start.
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Reduced Fuel Economy: When an ignition coil fails to fire the spark plug properly, unburned fuel can exit the combustion chamber, leading to decreased gas mileage.
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Lack of Power/Slow Acceleration: A misfiring cylinder robs the engine of power, leading to sluggish acceleration and an overall feeling of the car being “slow.”
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Engine Backfiring: Unburned fuel can ignite in the exhaust system, causing loud banging noises from the tailpipe. You might also smell gas or see black smoke.
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Sudden Stalling: If an ignition coil completely fails, the corresponding cylinder will stop firing, which can cause the engine to stall unexpectedly.
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Peculiar Noises: You might hear coughing, spluttering, or other unusual sounds from the engine.
