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A failing exhaust manifold can cause noise, reduced engine efficiency, and potential emissions issues, so picking the right replacement matters. This guide helps you identify Scion xB exhaust manifold options that match the vehicle's fitment and intended use. We shortlisted top-performing choices based on build quality, fit, and long-term reliability. Below you will find clear criteria we used to evaluate each option and a concise roundup of the best manifolds for this model.
Looking for other parts? See all Scion xB parts & accessories.
Top Picks at a Glance
| Best Reviewed A top-rated pick with lots of positive feedback | KAC Catalytic Converter with Exhaust Manifold for Scion xB / Toyota RAV4 (Front) |  |
| Best Quality Built to a higher standard if you want something more solid | Dorman 674-915 Driver Side Exhaust Manifold Kit with Gaskets and Hardware |  |
| Best Budget The cheapest option that still gets the job done reliably | Inracity 674-940 Cast Iron Exhaust Manifold Kit with Gasket and Hardware |  |
| Most Sold A high-volume bestseller chosen again and again | Dorman 674-803 Exhaust Manifold Kit (includes gaskets and hardware) |  |
| Best Value for Money The sweet spot between price and what you get | Weonefit Exhaust Manifold with Catalytic Converter Replacement |  |
| Best Overall The best all-around choice for most situations | A-Premium Exhaust Manifold Kit with Gaskets and Hardware |  |
1. KAC Catalytic Converter with Exhaust Manifold for Scion xB / Toyota RAV4 (Front)
| Position | Front |
|---|---|
| Oxygen Hole | 1 |
| Shell Material | Industrial Grade Stainless Steel |
| Substrate Material | Ceramic |
| Certification | EPA OBD-II Approved |
This KAC catalytic converter with integrated exhaust manifold is intended as a direct bolt-on replacement for the front converter on Scion xB 2008–2015 2.4L and RAV4 2006–2008 2.4L (use Scion xB fitment for this article). It pairs a ceramic substrate and high-performance catalysts made from rare earth and precious metals with an industrial-grade stainless steel shell and laser-welded joints for corrosion and heat resistance. The unit is EPA OBD-II approved, ships with gaskets and mounting hardware, and is designed for a bolt-down installation with one oxygen sensor port. In practice this means it should restore emissions performance, clear P0420-type codes when the original converter has failed, and maintain factory emissions compliance on federal models. Users report generally good fit when matching year and submodel, though some installers noted differences in heat-shield bolts and occasional minor alignment adjustments at the flange. Installation can require cutting or grinding of old fasteners on older cars, so expect a multi-hour job if rusted hardware is present. This is a practical, reliability-focused replacement that aims to match factory function while improving conversion efficiency compared with basic aftermarket cores.
Best for: A reliability-focused buyer who prioritizes restoring factory emissions performance and long-term durability on a Scion xB 2008–2015 2.4L, and who prefers a direct-fit, factory-replacement approach over custom solutions.
Less Ideal for: Buyers in states with their own emissions rules or those seeking a performance-tuned aftermarket exhaust component should look elsewhere.
- EPA OBD-II approved for federal emissions compliance
- Integrated exhaust manifold and bolt-on design simplifies replacement
- Industrial-grade stainless steel shell with laser-welded joints for corrosion and heat resistance
- High-flow ceramic substrate with rare earth and precious-metal catalysts for improved conversion efficiency
- Ships with gaskets and installation hardware for a complete replacement
- Not legal for sale or use in California, New York, and Maine
- Some users report mismatched heat-shield bolts or small alignment gaps that require minor adjustments
- Installation can be time consuming on older cars due to corroded exhaust fasteners
Verdict A reliable, EPA-approved direct-fit front catalytic converter with integrated manifold that restores emissions function on compatible Scion xB models while emphasizing durability.
2. Dorman 674-915 Driver Side Exhaust Manifold Kit with Gaskets and Hardware
| Manufacturer | Dorman Products |
|---|---|
| Model | 674-915 |
| Position | Center |
| Exterior | Machined |
This Dorman manifold kit is a ready-to-install replacement designed to restore a leaking or cracked exhaust manifold on supported vehicles. It arrives with the heat shield, gasket and downpipe hardware needed to complete the repair without hunting for additional parts. In everyday use it functions as a factory-style replacement: it bolts to the head, seals against exhaust leaks and routes exhaust gases to the downpipe. Notable features include machined mating surfaces and included gaskets that simplify installation and reduce the risk of leaks, plus reverse-engineering to match factory fitment. Practical benefits are faster repair times and lower cost compared with buying separate parts. Limitations to keep in mind are variable quality control reported by some buyers and that head-to-manifold mounting bolts are not always included, so you may need new fasteners; also some installers prefer to use a premium aftermarket gasket set for a longer-lasting seal. For performance-focused owners, it provides a solid factory-style replacement rather than a performance upgrade or port-matched race manifold.
Best for: Performance-oriented owners who prioritize restoring factory exhaust flow and sealing with a cost-effective, ready-to-install replacement to get their Scion xB back on the road quickly.
Less Ideal for: Buyers seeking a port-matched or free-flow performance manifold for power gains or those wanting a guaranteed premium fit without inspecting incoming castings should look elsewhere.
- Includes all required gaskets and downpipe hardware for a complete repair out of the box
- Machined mating surfaces and factory-directed design for straightforward fit and sealing
- Lower-cost direct replacement compared with dealer-sourced factory parts
- Heat shield included to reduce noise and protect nearby components
- Head-to-manifold mounting bolts may not be provided so additional fasteners can be required
- Some buyers reported inconsistent casting/fit quality on a small number of units
Verdict A practical, lower-cost factory-style replacement that restores sealing and function for owners who want a reliable repair rather than performance gains.
3. Inracity 674-940 Cast Iron Exhaust Manifold Kit with Gasket and Hardware
| Fitment reference | 674-940, 12609823 |
|---|---|
| Compatible engines | 2.4L L4 |
| Exterior | Milled |
| Manufacturer | Inracity |
This Inracity exhaust manifold kit is a straightforward cast-iron replacement intended to restore the exhaust header on compatible 2.4L four-cylinder Scion xB engines. It separates each cylinder’s exhaust path to reduce backpressure and help the engine run more efficiently after a damaged or leaking factory manifold is removed. The kit ships with a metal gasket and mounting bolts and nuts so you have what you need for a direct-fit installation in many routine repair scenarios. The milled cast-iron construction is durable and resists high exhaust temperatures, which is what you want for a long-lasting repair. Buyers should note the included gasket is basic and some installers prefer a higher-quality aftermarket gasket for a more reliable seal. A few customers reported cosmetic blemishes or packaging damage on arrival, so inspect the part and gasket before installation. For a budget repair that gets the job done with factory-style materials, this manifold offers a practical balance of durability and value for Scion xB owners with the specified 2.4L engine.
Best for: A budget-conscious buyer who wants a factory-style replacement to get a 2.4L Scion xB back on the road without paying for premium aftermarket brands.
Less Ideal for: Drivers seeking a performance-upgrade manifold or a fully premium kit with high-end gaskets and cosmetic finish should consider higher-tier alternatives.
- Cast iron construction suited for high heat and exhaust gases
- Includes gasket and basic bolts and nuts for immediate installation
- Milled exterior suggests consistent flange surfaces for better sealing
- Direct-replacement design intended for the specified 2.4L four-cylinder fitment
- Lower-cost option compared with many branded replacement manifolds
- Included gasket quality is basic and some installers replace it before installation
- Occasional cosmetic damage or minor casting marks reported on arrival
Verdict A cost-effective, cast-iron factory-style replacement that restores function for 2.4L Scion xB engines but may benefit from an upgraded gasket for long-term sealing.
4. Dorman 674-803 Exhaust Manifold Kit (includes gaskets and hardware)
| Compatible vehicles | Scion xA (2004-2006); Scion xB (2004-2006); Toyota Echo (2000-2005) |
|---|---|
| Includes | Gaskets and downpipe hardware |
| Position | Center |
This Dorman manifold kit is designed as a full replacement for the factory exhaust manifold on compatible Scion xB and xA models. It replaces a damaged or cracked manifold and ships with the gaskets, spring bolts, and downpipe hardware required to complete the job without separate parts orders. Typical use is a bolt-on repair during a head or exhaust service where the old manifold is removed; the part is reverse-engineered to match factory fitment so installation is straightforward for a competent DIYer or an independent shop. Practical benefits include complete hardware in the box to avoid trips to the parts store and construction intended to resist warping and leaks for a reliable seal. Limitations to note are occasional reports of inconsistent weld quality and a few units missing the advertised gasket, so inspect the kit on arrival and be prepared for quality checks; one buyer reported a broken weld and fit differences with the exhaust donut. The manifold is a budget-friendly, ready-to-install option when you need a timely repair for a Scion xB.
Best for: Risk-averse mainstream buyers who prioritize a straightforward, complete repair solution and prefer a ready-made kit that minimizes follow-up parts orders and service downtime.
Less Ideal for: Owners seeking a premium performance manifold or a guaranteed flawless cosmetic finish should consider higher-end or upgraded options rather than this value-focused replacement.
- Complete kit includes manifold gasket, flange hardware, and spring bolts so you can finish the repair with one part.
- Engineered to match factory fit and function for direct replacement on compatible Scion models.
- Durable construction aimed at reducing warping and leaks compared with worn originals.
- Ready-to-paint exterior lets you match appearance if aesthetics are a concern.
- Some buyers reported inconsistent welds or a broken weld on arrival indicating occasional quality control issues.
- A few orders arrived missing the manifold gasket or components despite listing, requiring inspection before installation.
Verdict A practical, all-in-one factory-fit replacement manifold for Scion xB owners who want a quick, budget-friendly repair, but inspect the unit on arrival for quality issues.
5. Weonefit Exhaust Manifold with Catalytic Converter Replacement
| Fitment note | Compatible with Honda Civic 1.7L 2001-2005 |
|---|---|
| Material | Stainless steel |
| Manufacturer | Weonefit |
| Manufacturer part numbers | 18160-PLM-A50, 18160-PLM-A00 |
This Weonefit exhaust manifold with an integrated catalytic converter is sold as a direct-fit replacement for 1.7L four-cylinder Civic engines from 2001 to 2005 and functions as a single-piece repair to restore exhaust routing and catalytic function. In practice it replaces a damaged or clogged factory manifold and converter assembly so you can clear exhaust leaks, stop rattles, and return the engine to normal backpressure. The unit is stainless steel and marketed for corrosion and heat resistance, and it includes the manifold, converter body and mounting flanges to minimize parts swapping during installation. Buyers report straightforward fitment and easier installation compared with sourcing separate components, which makes it practical for a budget repair or DIY swap. Important limitations are emissions compliance and durability: the listing warns it is not legal for sale in California and some users have seen persistent check-engine codes or early failures on certain installs, so it may not meet strict emissions or long-term OEM equivalence. Expect a cost-effective fix that may require follow-up if your vehicle is subject to rigorous emissions testing.
Best for: Practical optimizers looking to restore exhaust function on an older vehicle on a tight budget and who prioritize getting the car running over meeting strict emissions certification.
Less Ideal for: Vehicle owners who need a certified emissions solution or who require long-term factory-quality durability should choose a factory-quality, emissions-approved replacement instead.
- Single-piece manifold and converter simplifies replacement and reduces installation time.
- Stainless steel construction resists rust and high temperatures better than basic mild-steel units.
- Designed to match factory mounting points so it can be installed using existing hardware and gaskets.
- Lower-cost alternative to dealer or OEM assemblies, suitable for budget repairs.
- Not CARB-compliant and explicitly restricted from sale in some states, so it cannot be used where strict emissions certification is required.
- Several user reports of recurring check-engine lights or premature converter failure indicate inconsistent emissions performance.
- Some included small hardware and gaskets may be lower quality, requiring reuse of factory parts for a secure fit.
Verdict A cost-conscious, single-piece manifold/converter replacement that can get an older engine back on the road quickly but is not a certified emissions solution for strict-regulation areas.
6. A-Premium Exhaust Manifold Kit with Gaskets and Hardware
| Manufacturer Part Number | APEMD116 |
|---|---|
| OEM Part Number | 674-940, 12609823 |
| Compatible Engine | L4 2.4L |
| Package Contents | Manifold, manifold gasket, flange gasket, 3 bolts, 3 nuts |
This A-Premium exhaust manifold kit supplies everything needed to replace a cracked or leaking manifold: the cast manifold itself plus a manifold gasket, flange gasket, three bolts and three nuts. In practice it is used as a direct-fit replacement to restore exhaust routing and stop exhaust leaks that cause noise, poor idle and cabin fumes. The part is cast to match factory mounting points and reviewers report consistent fitment and compatibility when the correct engine and model are selected. The included gaskets and hardware simplify installation and reduce the need to source extra parts. Build appears solid for a replacement unit and the manufacturer offers a one-year unlimited-mileage guarantee. Limitations to expect are typical of aftermarket cast manifolds: occasional surface blemishes from the casting process and an uncertain long-term life compared with a factory assembly on engines known to develop manifold cracks. Also the kit lists specific vehicle fitment, so verify compatibility for your exact Scion xB engine before ordering.
Best for: Balanced owners who prioritize a straightforward, complete replacement that gets their vehicle back to normal without hunting for extra parts.
Less Ideal for: Drivers seeking a guaranteed long-term factory-grade manifold solution for chronic cracked-manifold engines or those wanting a performance-upgraded exhaust part should look elsewhere.
- Complete kit includes manifold, manifold gasket, flange gasket and necessary bolts and nuts for installation.
- Cast construction that resists heat and corrosion to restore proper exhaust function.
- Reported direct-fit match to factory mounting points simplifies installation for a replacement job.
- Aftermarket casting can show cosmetic dings or blemishes not present on factory parts.
- Long-term durability on engines prone to manifold cracking is uncertain compared with original factory units.
Verdict A practical, all-in-one replacement manifold kit that simplifies a repair but may not match factory longevity on engines prone to cracking.
Choosing the Right Scion xB Exhaust Manifold: Key Factors to Consider
Fitment and Bolt Pattern
Accurate flange alignment and bolt pattern matching are essential for a leak-free installation. If the manifold does not line up precisely with the cylinder head and exhaust system, you may face exhaust leaks, stress on mounting studs, or difficulty tightening hardware.
Fitment affects how straightforward the replacement will be and whether additional modifications or adapters are required. Prioritize manifolds specified for the Scion xB to minimize installation headaches and the risk of long-term sealing problems.
Material and Heat Resistance
Manifolds are commonly made from cast iron, stainless steel, or tubular steel, and each material behaves differently under heat cycles. Materials with higher thermal resistance are less likely to crack or warp over time, which preserves sealing and alignment.
Consider coatings and heat treatments that reduce corrosion and manage heat soak into nearby components. For vehicles driven in high-heat or corrosive environments, choose materials and finishes that extend service life and require less maintenance.
Gasket Surface and Sealing Design
The quality of the gasket surface and how the manifold interfaces with the cylinder head determine the likelihood of leaks. Smooth, flat mating surfaces and well-machined flanges help gaskets seat properly and maintain a seal through thermal expansion.
Design features such as raised or recessed flanges, integrated sealing surfaces, and compatibility with OEM-style gaskets should factor into your decision. A design that simplifies proper torqueing of fasteners will reduce the chance of uneven compression and subsequent leaks.
Thermal Management and Heat Shielding
Exhaust manifolds transfer a lot of heat to the engine bay, which can affect nearby sensors, wiring, and intake components. Effective thermal management reduces the risk of heat-related failures and can improve under-hood temperatures.
Look for manifolds that manage heat via material choice, integrated heat shields, or surface coatings. Consider how the manifold's heat output interacts with insulation and existing engine bay components to avoid heat soak and premature wear.
Durability and Resistance to Cracks
Repeated heating and cooling cycles place stress on manifold materials and can lead to cracking over time. Designs and materials that resist thermal fatigue help maintain performance and reduce the need for frequent replacements.
Evaluate manufacturing quality, such as consistent wall thickness, reinforced mounting points, and proven welding or casting methods. These factors influence how well the manifold resists cracks and stays serviceable across many miles.
Installation Complexity and Hardware
Some manifolds are engineered for straightforward bolt-on installation, while others require additional hardware, studs, or modifications. Ease of installation affects labor time and the potential for installation errors that could cause leaks.
Check whether the manifold comes with necessary gaskets, studs, or instructions and whether it requires special tools. Choosing a manifold with clear installation guidance and hardware that matches the Scion xB's specifications reduces DIY complications and shop labor.
FAQ
What are common exhaust manifold symptoms I should watch for?
Common signs include a ticking or tapping noise that changes with engine speed, reduced engine responsiveness, and a noticeable change in exhaust tone. You may also detect exhaust odor in the engine bay or reduced fuel efficiency. These symptoms often indicate a sealing problem or crack in the manifold.
How can I diagnose an exhaust manifold leak on a Scion xB?
Diagnosis usually starts with a visual inspection for soot, cracks, or damaged gaskets at the flange areas. Listening for a high-pitched leak noise while the engine is running and using a smoke test or a handheld stethoscope can help pinpoint leaks. In some cases, observing changes in performance or emissions readings can also indicate a problem.
When should I replace the exhaust manifold gasket versus the entire manifold?
If the mating surfaces are flat and undamaged and the leak is confined to the gasket area, replacing the gasket can resolve the issue. If there is visible cracking, significant warping, or recurring leaks after gasket replacement, replacing the entire manifold is usually the more reliable long-term solution.
Are OEM manifolds better than aftermarket options?
OEM and aftermarket manifolds each have tradeoffs. OEM units are designed to match original fitment and materials, which can simplify installation. Aftermarket options may offer different materials or improved flow but can vary in fit and finish. The best choice depends on desired durability, fit requirements, and any performance goals.
Will swapping the exhaust manifold affect engine performance?
Swapping to a manifold with different flow characteristics can influence backpressure and scavenging, which may have minor effects on low-end torque or throttle response. For general replacement, matching the original flow profile and fitment usually preserves stock performance while restoring proper sealing.
What should I budget for installation and associated costs?
Installation complexity varies with the vehicle and shop labor rates. Expect longer labor if access is tight or if studs and hardware need replacement. Costs also depend on whether additional parts like gaskets or heat shields are required. Getting a written estimate that lists labor hours and parts will clarify expected expenses.
How We Chose the Best Scion xB Exhaust Manifold
We prioritized components that ensure correct fit and longevity on the Scion xB. Key evaluation criteria included flange alignment and bolt pattern accuracy to guarantee straightforward installation, material and coating quality to resist warping and corrosion, and port matching to preserve exhaust flow characteristics. We also considered manufacturing tolerances that affect sealing, the design of mounting surfaces relevant to gasket performance, and overall construction that influences heat management. We excluded parts with unclear fitment data, nonstandard bolt patterns, or insufficient manufacturing information. Units intended only for racing or heavy modification were filtered out unless they also offered reliable street fitment. The resulting list focuses on manifolds that deliver dependable sealing, service life, and compatibility with the Scion xB's exhaust layout.
Our full evaluation process is outlined in our review methodology.
Conclusion
When choosing a replacement exhaust manifold for a Scion xB, focus first on correct fitment and flange alignment to prevent leaks. Balance material durability and thermal behavior with how the part will be installed and maintained. Consider gasket surface quality, resistance to cracking, and whether the unit includes appropriate hardware. Prioritizing these factors will help you restore exhaust flow and reduce noise while avoiding repeated repairs.
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