If the check engine light is on and the diagnostic code points to a failing 2008 Honda Odyssey catalytic converter, you’re looking at a straightforward but important repair. Common symptoms include sluggish acceleration, a sulfur smell from the exhaust, and reduced fuel economy. The 3.5L V6 uses two converters — Bank 1 and Bank 2 — built into the exhaust manifold system. Replacing them restores performance, kills the check engine light, and keeps the vehicle legal for emissions testing. Here is what fits, what it costs, and what the installation involves so you can make an informed call.
Which Catalytic Converter Fits The 2008 Honda Odyssey?
If you are looking at aftermarket options, the key requirement is CARB or EPA compliance. California and CARB-state vehicles require a CARB-certified unit, while other states can use EPA-compliant converters.
Two solid aftermarket options from MagnaFlow are worth knowing. Both must be verified for O2 sensor hole count and mounting bracket compatibility against your specific vehicle before purchase — the 2008 Odyssey has specific configurations that not every universal converter matches.
What Is The Real Cost To Replace It?
Parts pricing breaks down across three tiers. The Honda OEM assembly is the priciest option but guarantees exact fit and includes both converters. Labor runs 1.5 to 2 hours at a shop, so figure $150–$300 on top of parts depending on local labor rates.
| Converter Option | Part Number | Approximate Price |
|---|---|---|
| Honda OEM (2005–2010) | 18160-RGW-A00 | Varies by dealer |
| MagnaFlow OEM Grade | 51893 | $532 |
| MagnaFlow High Flow | — | $352 |
For a hands-on comparison of the most reliable aftermarket converters with verified fitment for the 2008 Odyssey, see our tested picks for this model.
How The Installation Works
The job is manageable for a confident DIYer with standard tools, but rusted bolts are the main wild card. Plan for 1.5 to 2 hours and gather penetrating oil, an O2 sensor socket, and basic hand tools before starting. The three critical bolts on the manifold are often rusted — penetrating oil applied the night before makes the difference between a smooth job and a snapped bolt headache.
Key steps in order:
- Remove the O2 sensor carefully using a dedicated O2 sensor socket to avoid damaging the threads
- Remove the three manifold bolts; use penetrating oil and gentle back-and-forth pressure — a torch is a last resort if rust is severe
- Remove the EGR tube if the design requires it; skipping this step can bend or crack the tube during converter removal
- Install the new converter with proper gasket and spring washer placement — misalignment here causes exhaust leaks
- Reinstall the O2 sensor and torque to spec; verify the connection before starting the engine
A few pitfalls to watch for: buying a converter with mismatched O2 sensor holes, forcing rusted bolts without penetrating oil, gasket misalignment that causes exhaust leaks, forgetting the EGR tube, and damaging the O2 sensor during removal. Take it slow on the bolts and double-check gasket placement before tightening everything down.
Safety note: if a torch becomes necessary, keep a fire extinguisher within reach and never direct flame at fuel lines, wiring, or brake lines. Secure the vehicle properly on jack stands — never work under a car supported only by a floor jack.
FAQs
How many catalytic converters does a 2008 Honda Odyssey have?
The 2008 Odyssey with the 3.5L V6 uses two catalytic converters, designated Bank 1 and Bank 2. Both are integrated into the exhaust manifold assembly, and the OEM replacement part covers both as a single unit.
Can I use a universal catalytic converter on my 2008 Odyssey?
A universal converter can work provided the O2 sensor hole count and mounting bracket layout match your vehicle’s exact configuration. For California and other CARB-regulated states, the converter must carry a CARB certification regardless of whether it is a direct-fit or universal type.
Will a bad catalytic converter damage my Odyssey’s engine?
A clogged or failing converter creates backpressure that reduces engine performance and fuel efficiency. Left unaddressed, it can eventually cause overheating and engine damage. Replacing it when the check engine light first appears prevents these downstream issues.
References & Sources
- MagnaFlow. “2008 Honda Odyssey Catalytic Converters.” Official fitment and product listings for OEM Grade and High Flow converters.
- Honda OEM Parts Online. “Honda Catalytic Converter 18160-RGW-A00.” OEM part number and application data for 2005–2010 Odyssey models.