Engines and Components› Camshafts and Valvetrain

HKS

HKS SUPER FIRE RACING M45i- Pack of 10 Spark Plugs

$270.00

SKU: H005 50003-M45I

In Stock
In Stock
Ships by Sep 16
Free Shipping over $200
$100 Minimum Order
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Overview

The HKS Super Fire Racing M45i is a high-performance iridium spark plug designed for enthusiasts seeking superior ignition performance and durability. It features a 0.6mm iridium alloy center electrode for concentrated spark energy and an outer electrode with a platinum chip for enhanced longevity. The nickel-coated housing prevents premature deterioration, and its construction tolerates extreme compression and minor detonation.
Show original supplier description

Part #: 50003-M45I

Vehicle Symptoms
  • Engine misfires under load
  • Rough idle when cold
  • Poor acceleration and hesitation
  • Decreased fuel economy
  • Check engine light flashing
Diagnostic Codes
  • P0300 – Random/multiple cylinder misfire detected
  • P0301 – Cylinder 1 misfire detected
  • P0302 – Cylinder 2 misfire detected
  • P0303 – Cylinder 3 misfire detected
  • P0304 – Cylinder 4 misfire detected
  • P0305 – Cylinder 5 misfire detected
  • P0306 – Cylinder 6 misfire detected
Relevant Conversations
  • Engine misfire at high RPM – best spark plug upgrade?
  • P0300 code after tune – HKS M45i vs NGK?
  • Rough idle and hesitation – spark plug replacement?
  • HKS Super Fire Racing spark plug review
  • Best iridium spark plugs for turbo Subaru
  • P0301 cylinder 1 misfire – should I replace all plugs?
  • How to gap HKS M45i spark plugs?
  • Misfire during acceleration – spark plugs or coils?
  • HKS 50003-M45I compatible with Honda K24?
  • Spark plug change interval for tuned cars

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandHKS
Part NumberH005 50003-M45I
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

Buy with Confidence

Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy

Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy