-10%
Click to zoom in
Performance Engineered in the USA: Proven Gains for Street and Track Builds
The Kooks CAS-109677-8 8-inch front oxygen sensor extension harness resolves the common issue of insufficient wiring length during header installations on 2018 and 2024 Ford Mustang GT models with the 5.0L Coyote V8, providing a plug-and-play 5-pin connection that repositions the upstream O2 sensor precisely for accurate air-fuel monitoring and ECU calibration without triggering check engine lights or lean/rich codes.
Precision-engineered from high-temperature shielded wiring with OEM-style connectors, this extension maintains signal integrity under extreme exhaust heat exceeding 1,200°F and vibration from high-RPM operation, ensuring reliable data transmission to the PCM for optimal performance mapping during dyno tunes or track sessions. The 8-inch length offers the exact reach needed for Kooks long-tube headers without excess slack that could cause chafing or shorts.
For Mustang GT owners upgrading to aftermarket headers who need a simple, reliable O2 relocation solution, the CAS-109677-8 harness delivers the essential wiring bridge for seamless installation and flawless engine management.
Key Features
- 8-inch length for precise front O2 sensor relocation
- 5-pin OEM-style connectors for plug-and-play fitment
- High-temperature shielded wiring rated over 1,200°F
- Vibration-resistant construction for track durability
- Maintains accurate air-fuel ratio readings and ECU function
- Direct replacement for lost or damaged extensions in header kits
Product Notes
- Front upstream sensor extension only rear requires separate harness
- Designed specifically for Kooks header installations on 2018+ Mustang GT
- Inspect connections regularly to prevent heat damage
California Proposition 65: Contains chemicals known to the State of California to cause cancer or reproductive harm.
Warranty: Limited lifetime against manufacturing defects to original purchaser.
Installation Notes
- Locate factory O2 harness and unplug sensor connector
- Route extension harness to new sensor location avoiding exhaust heat
- Plug into OEM harness and sensor hand-tight secure with zip ties
- Clear any codes and perform drive cycle for ECU relearn
This Part Fits
| Year | Make | Model | Submodel/Engine |
|---|---|---|---|
| 2018 and 2024 | Ford | Mustang | GT 5.0L Coyote V8 (4V) |
Note: Front upstream O2 extension for Kooks header kits. Use with 2018+ Mustang GT 5.0L only.
What's Included in the Purchase
- (1) 8-Inch 5-Pin Oxygen Sensor Extension Harness
- Part Number: Kooks CAS-109677-8
Why Choose Kooks?
- Over 60 years of championship-winning exhaust engineering
- Precision wiring components tested in 1,000+ HP builds
- Limited lifetime warranty and expert installation support
Frequently Asked Questions
-
Q: Is this for front or rear O2 sensors?
A: Front upstream only rear requires CAS-105979 or equivalent -
Q: Will it work with non-Kooks headers?
A: Yes, fits any 2018+ Mustang GT header with 5-pin O2 relocation -
Q: Does it affect tuning?
A: No, maintains OEM signal quality for accurate ECU readings -
Do Kooks headers require a tune after installation?
Yes. A professional tune is strongly recommended after installing long tube headers. The significant improvement in exhaust flow changes air fuel ratios and requires ECM recalibration to achieve optimal power output and safe operation. -
Will these headers void my factory powertrain warranty?
Under the Magnuson-Moss Warranty Act, a manufacturer cannot void your vehicle warranty simply because you installed an aftermarket part unless they prove the component directly caused the failure. Consult your dealer for specifics on your situation. -
Q: Do these Kooks headers require a tune after installation?
A: Yes. A professional tune is strongly recommended after installing long tube headers. The significant improvement in exhaust flow changes air fuel ratios and requires ECM recalibration to achieve optimal power output and safe operation. -
Q: Will Kooks headers void my factory powertrain warranty?
A: Under the Magnuson-Moss Warranty Act, a manufacturer cannot void your vehicle warranty simply because you installed an aftermarket part unless they prove the component directly caused the failure in question. Consult your dealer for specifics. -
Q: What warranty does Kooks provide?
A: Kooks products are backed by a limited lifetime warranty to the original purchaser against defects in materials and workmanship. Racing and competition use applications may have specific warranty exclusions. Contact Kooks Performance directly for warranty details.
Shipping & Handling
- Method: UPS or Fed Ex Ground.
- Availability: Typically ships same day or next if in stock.
- Packaging: Anti-static bag in protective box.
Exhaust Components
Exhaust Hardware & Performance Exhaust Parts Upgrade your vehicle with premium exhaust components, exhaust hardware, and performance exhaust parts. This collection includes high-quality exhaust gaskets, exhaust adapters, exhaust cutouts, exhaust hangers, exhaust wrap, oxygen sensors, and valve controllers designed to improve exhaust flow, durability, and overall system performance. Exhaust Components from Top Brands Shop trusted brands including Vibrant Performance, DEI, BD Diesel, BLOX Racing, MAHLE, Victor Reinz, NGK, AWE Tuning, Akrapovic, Granatelli, and Torque Solution. These brands are trusted for street performance, diesel applications, turbo builds, and custom exhaust fabrication. Shop Exhaust Components by Category Find exhaust gaskets (MLS, manifold, turbo, and flange gaskets), exhaust adapters and fittings, exhaust cutouts and valve systems, exhaust hangers and mounting hardware, exhaust wrap and heat shielding, O2 sensors and emissions components, exhaust brakes and ...
View Exhaust Components Products
Exhaust Systems
Black Ops Auto Works carries one of the largest selections of performance exhaust systems available online, with 7,700+ products covering cat-back exhausts, axle-back exhausts, turbo-back systems, downpipes, headers, mid-pipes, X-pipes, H-pipes, mufflers, resonators, catalytic converters, exhaust tips, and every component in between. Whether you're building a street car, a daily driver, a diesel truck, or a track build, the right exhaust upgrade is here. Shop by Exhaust System Type Cat-Back Exhaust Systems: The most popular performance exhaust upgrade. Replaces everything from the catalytic converter back for improved sound, better flow, and premium tip styling. Available in single exit, dual exit, and quad exit configurations. Axle-Back Exhaust Systems: A simpler bolt-on that replaces the rear section from the axle back. Best for drivers who want an improved exhaust note and cleaner tip appearance without a full system swap. Headers and Manifolds: Long tube headers and shorty h...
View Exhaust Systems Products
Ford Mustang Parts & Accessories
Shop Ford Mustang parts and accessories at Black Ops Auto Works for premium aftermarket performance parts, suspension upgrades, brake kits, exhaust systems, cold air intakes, carbon fiber body parts, lighting upgrades, fuel system components, and styling accessories. Whether you drive a classic Ford Mustang, SN95, New Edge, S197, S550, S650, Mustang EcoBoost, Mustang GT, Mach 1, Shelby GT350, Shelby GT500, or Dark Horse, this collection is built for enthusiasts who want better power, handling, braking, airflow, drivability, and aggressive styling. From daily-driven street cars to drag builds, track cars, and show cars, our selection of Ford Mustang aftermarket parts is curated for fitment, quality, and performance. Shop Ford Mustang Performance Parts by Category Browse Mustang performance parts across popular upgrade categories, including: Ford Mustang cold air intakes and intake parts Ford Mustang brake pads, brake rotors, and brake kits Ford Mustang exhaust systems, cat-back exha...
View Ford Mustang Parts & Accessories Products
Kooks Exhaust
Shop Kooks Headers and Kooks Exhaust products at Black Ops Auto Works for premium American-made exhaust systems, long tube headers, shorty headers, cat-back exhaust systems, axle-back exhaust systems, connection pipes, catted connection pipes, and performance exhaust components built for street, strip, and track applications. With decades of motorsports heritage, Kooks is trusted by enthusiasts, engine builders, and racers looking for high-quality stainless steel exhaust upgrades with proven fitment and performance. American-Made Kooks Performance Exhaust Founded in 1962, Kooks Headers has earned a strong reputation for USA-made exhaust performance, precision craftsmanship, and race-proven durability. Kooks products are manufactured using premium stainless steel and designed to support improved exhaust flow, aggressive sound, and reliable long-term performance on high-horsepower builds. Shop Kooks Headers & Exhaust Parts by Category Browse Kooks exhaust components and performanc...
View Kooks Exhaust Products
Oxygen Sensors
Welcome to our exclusive collection of Oxygen Sensors for your vehicle's exhaust. These essential components play a critical role in maintaining your vehicle’s performance and efficiency by accurately measuring the amount of oxygen in the exhaust gases. Our carefully curated selection ensures you’ll find the perfect sensor to fit your needs. Why Choose Our Oxygen Sensors? High Quality: Each sensor is made from durable materials to withstand extreme conditions. Precision Engineering: Designed for accurate readings to improve fuel efficiency and reduce emissions. Easy Installation: Most of our sensors come with straightforward instructions for a hassle-free setup. Compatibility: Wide variety of sensors available to fit numerous vehicle makes and models. Benefits of Replacing Your Oxygen Sensors Replacing worn or faulty oxygen sensors can lead to: Improved fuel economy Enhanced engine performance Lower emissions Better overall vehicle health Shop Our Collection Bro...
View Oxygen Sensors ProductsLet customers speak for us
Looks pretty nice
Looks pretty nice, pricing was good and the reinforcement is a big plus.
Randy H.
Black Ops Auto Works
I emailed customer service to inquire about when it would be shipped
I emailed customer service to inquire about when it would be shipped. They checked and emailed me with the answer. Customer service is A1
Ralph J.
Black Ops Auto Works
Installation was easy
Installation was easy. The price is good and it looks great on the truck.
Ralph J.
RHO Small Grille Badge
Looks as good as it fits
Looks as good as it fits,
zachary d.
Seibon 70-73 Datsun 240Z OE Carbon Fiber Hood
Nothing like it
I love it great sound and response
Luis P.
Legmaker Dodge Durango HEMI Short Ram CAI 2011-Present 5.7L
Car totally diferent with the whole kit
Car totally diferent with the whole kit. Ive stood next to wide bodies and my car gets more attention at times . Ive bought the kit twice already.
Ding D.
2015-2023 Dodge Charger Carbon Fiber Wind Splitters
Fantastic emblem! Exactly what I was looking for
Fantastic emblem! Exactly what I was looking for. Great quality emblem.
Jacobus S.
Direct Connection Black Metallic Fender Badge
Worked great for my aftermarket hood on my Chrysler 2023 300C
Worked great for my aftermarket hood on my Chrysler 2023 300C. Thanks
Robert G.
Windshield Washer Squirter Relocation Kit Universal
Easy to install and makes car sound even better
Easy to install and makes car sound even better love the winn
Tracy H.
Legmaker Challenger/Charger Hellcat Demon & Redeye Air Intake
Awesome customer support
Awesome customer support. Had multiple issues with fedex and these guys were excellent in helping me sort everything out. The drop springs are great too! I highly recommend
Anonymous
Swift Spec-R Lowering springs Jeep Grand Cherokee 2011-2021
100/100! perfect CF crafted cold air intake for 6
100/100! perfect CF crafted cold air intake for 6.4 jeep .. even makes my AWE exhaust sound even deeper and you cam here this thing sucking when accelerating even at normal speeds🥶
srt.boizzz
Legmaker 392 TH Short Ram Jeep Grand Cherokee SRT 2012-2021
