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Bosch 7403 - Spark Plug
Product Overview
Experience the superior performance and reliability of Bosch Spark Plugs, specifically engineered for high-performance Porsche vehicles. The Bosch 7403 Spark Plug (Super Plus) is designed to ensure optimal ignition, providing a crucial role in engine performance by igniting the air-fuel mixture efficiently. This premium-grade spark plug is constructed to OEM standards, ensuring a perfect fit and long-lasting service life. Typical service intervals for standard copper tip spark plugs range between 10,000 and 30,000 miles, making regular replacement essential for maintaining your engine's health. Choose Bosch 7403 for dependable performance and peace of mind every time you service your vehicle.
Cross Reference Numbers
This Bosch 7403 is equivalent to or replaces the following part numbers: 999 170 183 90, 99917018390.
Vehicle Compatibility
- Porsche 911 Carrera 2 3.6 H6 (1990–1995)
- Porsche 911 Carrera 4 3.6 H6 (1990–1995)
- Porsche 911 Turbo 3.3 H6 (1992)
- Porsche 911 Turbo 3.6 H6 (1994)
- Porsche 911 RS America 3.6 H6 (1993–1994)
- Porsche 911 Speedster 3.6 H6 (1994)
This may also fit other applications. Please use the vehicle selector tool to verify fitment.
Why Shop at eEuroparts.com?
- Proven Expertise: Over 25 years of experience with European vehicles means we know your car inside and out.
- Exclusive Kits That Fitâ„¢ - complete repair solutions with no guesswork
- Fitment Confidence: Our accurate cataloging ensures you get the right part the first time.
- Fast, Reliable Shipping: Orders ship quickly from our U.S.-based warehouses.
- Transparent Pricing: Competitive prices with no hidden fees or surprise charges.
- Established Trust: Serving the European auto community since 2000.
Frequently Asked Questions
What does the Bosch 7403 Spark Plug do?
The Bosch Spark Plug is a critical component in your vehicle's ignition system. It ignites the air-fuel mixture in the engine's combustion chamber, converting it into the energy required to power your vehicle. A properly functioning spark plug ensures smooth engine operation and optimal performance.
How do I know if my Spark Plug needs replacement?
Common signs that your spark plugs may need replacement include engine misfires, rough idling, poor acceleration, decreased fuel efficiency, and difficulty starting the engine. If you experience any of these symptoms, it may be time to replace your spark plugs.
Can I install the Bosch 7403 myself?
Yes, the Bosch 7403 Spark Plug can be installed as a DIY project. However, it is important to follow proper installation guidelines and ensure that the spark plugs are correctly gapped before installation for optimal performance.
What are the symptoms of a faulty Spark Plug?
Symptoms of a faulty spark plug include engine misfires, rough running, and decreased fuel efficiency. If you see DTCs such as P0300, P0301, P0302, P0303, it may indicate a failing spark plug. It is crucial to address these issues promptly to maintain vehicle performance.
Why should I choose Bosch for my Spark Plug needs?
Choosing Bosch means opting for proven quality and reliability. With their extensive expertise in automotive components, Bosch ensures that you receive a product that meets or exceeds OEM specifications. Order Bosch 7403 today for a factory-correct replacement that restores safety and performance.
Note: All information on this page and in the FAQ is for general reference only. Verify fitment and consult a professional as needed. eEuroparts.com is not responsible for incorrect part selection or installation.
- BrandBosch
- ManufacturerBosch
- MPN7403
- Part TypeSpark Plug
- OE Part Numbers999 170 183 90, 99917018390, 999 170 178 90, 99917017890, 999 170 182 90, 99917018290
- Cross Reference NumbersFR5DTC, FR 5 DTC, 0 242 245 539, 0242245539, 7403
- FeaturesCenter Electrode Design : Standard
Electrical Terminal Type : Non-Removable Nut
Ground Configuration : Multiple
Ground Electrode Core Material : N/A
Ground Electrode Quantity : 3
Ground Electrode Tip Design : Multiple
Hex Size : 16
Hex Type : Hex
Indexed : No
Insulator Material : Ceramic
Insulator Type : Non-Projected
Manufacturer Heat Range : 5
Outdoor Power Equipment Application : No
Package Contents : Spark Plug
Package Quantity : 1
Pre-Gap Size : .8
Product Length : 2.948819 in
Product Width : 0.748031 in
Prop 65 Warning Label Required? : No
Reach : 19
Resistance : 6000
Resistor : Yes
Resistor Type : Yes
Seat Type : Flat
Short Style : No
Spark Plug Type : 4-Cycle
Thread Diameter : 14
- Fitment
- Fitment TypeVehicle Specific
| Year | Make | Model | Submodel | Notes |
|---|---|---|---|---|
| 1989 | Porsche | 911 | Carrera 4 (3.6 H6 GAS) | Notes: Original Center Electrode Material is Copper/Nickel, Do Not Gap, Gap is Preset |
| 1990 | Porsche | 911 | Carrera 2 (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1990 | Porsche | 911 | Carrera 4 (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1991 | Porsche | 911 | Carrera 2 (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1991 | Porsche | 911 | Carrera 4 (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1992 | Porsche | 911 | Turbo (3.3 H6 GAS) | Notes: Original Center Electrode Material is Copper/Nickel, Do Not Gap, Gap is Preset |
| 1992 | Porsche | 911 | Carrera 2 (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1992 | Porsche | 911 | Carrera 4 (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1993 | Porsche | 911 | Carrera 2 (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Original Center Electrode Material is Copper/Nickel, Do Not Gap, Gap is Preset |
| 1993 | Porsche | 911 | Carrera 4 (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Original Center Electrode Material is Copper/Nickel, Do Not Gap, Gap is Preset |
| 1993 | Porsche | 911 | RS America (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Original Center Electrode Material is Copper/Nickel, Do Not Gap, Gap is Preset |
| 1993 | Porsche | 911 | Turbo 3.6 (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Original Center Electrode Material is Copper/Nickel, Do Not Gap, Gap is Preset |
| 1994 | Porsche | 911 | Carrera 2 (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1994 | Porsche | 911 | Carrera 4 (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1994 | Porsche | 911 | RS America (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1994 | Porsche | 911 | Speedster (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1994 | Porsche | 911 | Turbo 3.6 (3.6 H6 GAS) | Aspiration: Naturally Aspirated, Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1995 | Porsche | 911 | Carrera (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
| 1995 | Porsche | 911 | Carrera 4 (3.6 H6 GAS) | Notes: Do Not Gap, Gap is Preset, Original Center Electrode Material is Copper/Nickel |
Warranty Overview
At eEuroparts, we stand behind the quality of the products we sell. Every part we offer is backed by a warranty designed to give you peace of mind and protect your investment.
Standard Warranty – Most Parts
Coverage: 2 years or 24,000 miles (whichever comes first) from purchase date.
Protection: Defects in materials or workmanship under normal personal use.
Eligibility: Applies only to the original purchaser and the vehicle where the part was first installed.
Exclusions:
Wear-and-tear items (brake pads, filters, bulbs, wipers, etc.)
Commercial, fleet, rideshare, off-road, or racing use
Improper installation, misuse, accidents, or modifications
Not Covered: Labor, shipping, towing, or incidental costs.
Bison Performance Warranty – Our House Brand
Coverage: Limited Lifetime Warranty for as long as you own your vehicle.
Applies To: All products sold under the Bison Performance label.
Premium Protection: Goes beyond our standard warranty — if it’s a Bison product, the 2-year/24k mile limit is replaced with lifetime coverage.
Exclusions: Same as the standard warranty (normal wear, commercial use, improper installation, etc.).
What’s Included: Replacement of the defective product (labor and shipping excluded).
Warranty Claim Requirements
To keep claims fast and fair, we require:
Proof of purchase (invoice or order confirmation).
Photos or videos showing the defective part, order number, date, VIN, and odometer reading.
Diagnostic reports or part returns for non-visible issues may be requested.
Claims must be truthful, properly documented, and reflect normal consumer use.
Buy With Confidence: We back our products because we believe in their quality, with a transparent, customer-first warranty process you can trust. And with Bison Performance products, you’ll enjoy Limited Lifetime protection—an assurance few brands can match.
For full details and exclusions, please see our complete Warranty Terms & Conditions.
This summary is for convenience only. For full warranty coverage details, exclusions, and requirements, see our official Warranty Terms & Conditions. In case of conflict, the full policy governs.
Return Policy Overview
Most parts can be returned within 30 days of delivery if unused, uninstalled, and in original packaging.
To start a return, contact customer support via Chat or Contact Us.
Restocking fee: Up to 20% may apply for certain orders (buyer’s remorse, order errors, or special-order items)
Refunds: Issued to your original payment method within 3–5 business days after inspection
Exchanges: Not automatic — please return and reorder
Replacements: May be approved for incorrect or defective items reported within 7 days
Not returnable:
Used or installed parts
Electrical components
Opened filter kits, gaskets, or contaminated items
Final sale or custom orders
Important Notes:
Return shipping is your responsibility unless we made a verified error
Fitment is the customer’s responsibility (we can assist, but do not guarantee)
Country of origin may vary and is not grounds for return
For complete details, please see our full Return Policy.
This Returns summary is provided for convenience only. All returns, refunds, and exchanges are subject to the complete Returns Policy. In the event of any conflict, the full policy governs.
Fast, Reliable Shipping — Straight to Your Door
We ship most orders the same day when placed before 2 PM CST (Monday–Friday). Our main warehouse is just east of Nashville, TN, and we also ship from multiple locations nationwide to get your order to you as quickly as possible.
We use trusted carriers like UPS, FedEx, and USPS.
Tracking info is emailed to you as soon as your order ships.
Delivery estimates at checkout are based on carrier data, but not guaranteed.
Need help with a shipment?
If your order is missing, damaged, or incorrect, just let us know within 5 days of delivery. We’ll walk you through the quick claim process — including a few photos to help us make things right.
For complete details, please see our full Shipping Policy.
This Shipping summary is provided for convenience only. Delivery times, carrier terms, fees, restrictions, risk of loss, and other details are governed by our complete Shipping Policy. In the event of any conflict, the full policy governs.
















