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The rattle under your Odyssey is getting louder, and that check-engine light is a permanent dashboard fixture. A bad catalytic converter kills your fuel economy and will eventually strand you at an emissions test, so picking the right replacement matters more than just the price tag.
I’m Min Islam — the founder and writer behind Trending Car. This guide is built by comparing the manufacturers’ published specifications and the patterns across verified customer reviews, so you get each pick’s real strengths and trade-offs instead of marketing spin.
Whether your Odyssey needs a direct bolt-on or a more involved install, these are the top options for the best 08 honda odyssey catalytic converter replacement.
Our Picks at a Glance
How To Choose The Best 08 Honda Odyssey Catalytic Converter
Your Odyssey’s 3.5L V6 is particular about exhaust flow, and not every aftermarket converter delivers the same fit or durability. Here is what to zero in on before you buy.
Fitment and OE Numbers
Every converter in this list is claimed to fit a 2008-2019 Odyssey 3.5L, but the specific OE interchange numbers (like 16658, 16643, 45131, 641413) tell you whether the bolt pattern and pipe routing match your exact chassis. Matching these numbers to your original part is the fastest way to avoid a return.
EPA Compliance and State Restrictions
Most aftermarket converters sold online are labeled “EPA Compliant” for federal standards, but that does not make them legal in California, New York, Colorado, or Maine. If you live in one of those states, you must buy a CARB-compliant unit — none of the picks here qualify.
Construction and Warranty
Stainless steel bodies and ceramic substrates with precious metal catalysts (platinum, rhodium, palladium) resist high heat and last longer. A lifetime or multi-year warranty (one pick offers 2.5-years or 25,000-miles) signals the maker’s confidence in the welds and internal structure.
Quick Comparison
| Model | Best For | Item Weight | Warranty | EPA Status | Amazon |
|---|---|---|---|---|---|
| FOMIUZY Kit (3-Piece)★ Best Overall | Complete hardware plus heavy build | 18.21 pounds | Lifetime | Federal only | Amazon |
| LELEHOKA Left & Right Pair | OEM-spec with high flow design | 12.62 pounds | Standard | EPA Certified | Amazon |
| ECHO AUTOMILES Single | 400-cell honeycomb + warranty | 12.2 pounds | 2.5-Year / 25k-Mile | EPA Compliant | Amazon |
In‑Depth Reviews
1. FOMIUZY Catalytic Converter Kit
Our pick — over 4★ from 350+ verified ratings; the strongest balance of quality and price.
The heaviest kit here at 18.21 pounds, built like a bank vault for your Odyssey’s exhaust.
If you want a set you can bolt on and forget about, this FOMIUZY three-piece kit is your strongest play. It includes the converter and matching hardware, and the stainless steel body with high-load precious metal catalysts (platinum, rhodium, palladium) is designed to handle high-temperature exhaust gases without degrading quickly. Buyers report that “it took me 5.5 hours to swap out the catalytic converter on my 2008 Honda CRV” and the fitment was accurate once they worked around the tight routing.
The package dimensions (16.42 x 14.48 x 6.26 inches) are noticeably larger than the other options, which makes sense given the 18.21-pound weight — at 18.21 pounds versus the 12.2-pound ECHO AUTOMILES unit. That extra mass comes from thicker steel and more substrate material. The only catch reported by owners is that the included front donut gasket was too small, and they had to buy a separate EXH 31673 gasket from a local parts store.
This converter is not legal for sale in California or New York, so double-check your state before ordering.
Solid Reasons To Buy
- Lifetime warranty — if it fails, the maker replaces it
- Heavy-duty stainless steel body resists rust and heat
- Covers a huge range of Honda and Acura V6 models
Watch Out For
- Front donut gasket is undersized, plan to buy a replacement
- Pipe routing can be tighter than OEM, making installation harder
Reach for this if: you want the most substantial build with a lifetime warranty and do not mind sourcing one extra gasket.
Look elsewhere if: you want a simple drop-in with zero extra parts or live in California or New York.
2. ECHO AUTOMILES Catalytic Converter
The 400-cell honeycomb inside this converter reduces backpressure while keeping emissions clean.
ECHO AUTOMILES engineered this single converter around an OEM-equivalent 400-cell honeycomb substrate — that means the exhaust gases flow through more channels per square inch, cutting backpressure so your 3.5L V6 breathes easier and fuel consumption can drop slightly. At 12.2 pounds it is the lightest pick on this list, which suggests a leaner build but not a flimsy one given the 4.2-star average from 218 ratings.
The kit includes necessary gaskets and hardware, and the 2.5-year or 25,000-mile warranty is the only fixed-term guarantee here — the FOMIUZY kit has a lifetime warranty by comparison. However, one reviewer noted “multiple leaks at weld points” and reported that the supplied hardware was incomplete (three studs and six bolts instead of the correct matching set). Other owners say the fit is “perfect just like oem” and call it a good value.
Remember: this converter is not legal for sale in California, Colorado, Maine, or New York.
Best for DIYers who want: a EPA-compliant converter with a defined warranty and the efficiency of a high-flow 400-cell substrate.
Grab it if: you prioritize emissions performance and want a known warranty period.
Skip if: you are not comfortable checking weld quality on arrival or live in a restricted state.
3. LELEHOKA Left & Right Catalytic Converter Pair
A pair of front-position converters with an EPA stamp and a high-flow design for more power.
LELEHOKA’s set positions itself as a performance-minded option — the “high flow design” is meant to feed more oxygen to the engine, which can improve throttle response and acceleration. At 12.62 pounds it is close to the ECHO AUTOMILES unit’s weight, and the package dimensions (14.37 x 10.94 x 5.98 inches) are the most compact in this lineup. The converters interchange with OE numbers 16658, 16643, 45131, and 45132, so they match a wide range of Honda and Acura V6 vehicles from 2008 onward.
Buyer experiences are split. One verified owner says “fits my 2003 Honda Accord, perfect and works great improved bad mileage and slow acceleration,” while another warns the product “didn’t help at all” and caused worse smoking after replacing O2 sensors. A separate buyer noted the engine light still appears occasionally but attributes it to a different catalytic converter on the vehicle.
The maker advises this unit is not for use in California, Colorado, New York, or Maine. Given the mixed reviews (3.7 stars, 33 ratings), this pick is best for someone who has already diagnosed their exact failure and is comfortable with potential variance in fitment.
What Stands Out
- High-flow design for potential performance gains
- Compact dimensions fit tight exhaust tunnels
- EPA certified to meet federal standards
What Gives Pause
- Inconsistent reviews — some customers note no improvement
- Check-engine light may persist after installation
Consider it if: you value a high-flow design and have already verified your stock converter is the root cause.
Avoid if: you want a proven reliable swap with fewer gamble reviews.
Understanding the Specs
EPA Compliance vs State Laws
EPA-compliant means the converter meets federal emission standards set by the Environmental Protection Agency. That is enough for most states, but California, New York, Colorado, and Maine have their own stricter rules (CARB standards in California). A converter labeled “EPA Compliant” is generally illegal to install in those four states. Always check your state’s regulations before buying.
Honeycomb Substrate and Cell Count
The ceramic honeycomb inside the converter holds precious metal catalysts that scrub pollutants from exhaust gas. A 400-cell substrate (like the ECHO AUTOMILES unit uses) has 400 channels per square inch — more cells means more surface area for chemical reactions, which improves purification while keeping exhaust flow efficient. The substrate material also needs to resist melting under high temperatures generated by the 3.5L V6.
FAQ
Will any of these converters fit my 2008 Honda Odyssey 3.5L?
Why are some converters not legal in California or New York?
How heavy should a good catalytic converter be for the Odyssey?
What does the 400-cell honeycomb structure do?
Do I need to replace gaskets when installing a new converter?
Can a bad catalytic converter cause slow acceleration?
How long does it take to swap a catalytic converter on an Odyssey?
What does a lifetime warranty on a converter actually cover?
Will a new catalytic converter fix my check-engine light?
What is the difference between a two-piece set and a single converter?
Final Thoughts: The Verdict
For most Odyssey owners, the 08 honda odyssey catalytic converter winner is the FOMIUZY Kit because it combines the heaviest build quality, a lifetime warranty, and broad Honda/Acura fitment. If you want a 400-cell substrate with a defined warranty period, grab the ECHO AUTOMILES. And for a budget-friendly two-piece swap, the LELEHOKA Pair is your cheapest entry point.
How We Picked
We do not accept paid placement. Every pick is matched to a real buyer and a real use-case; we do not hands-on test units.
Sources & Methodology
Specifications: manufacturer listings and product documentation. Review insights: verified customer reviews, as of July 2026. Pricing: not shown on this page (it changes often); check the current price via the retailer link.
As an Amazon Associate, Trending Car earns from qualifying purchases. This does not affect which products we feature.