P0420 Repair Cost on a Toyota Camry

What you are really paying for

The code does not tell a shop what to replace, so the first bill is often diagnosis. The repair that follows depends on the root cause found, and the same code can lead to very different invoices:

These numbers measure different things. YourMechanic’s averages reflect a mobile service and aftermarket parts; RepairPal’s range reflects shop labor rates and typical parts for the model. Neither is a quote for your car, and neither covers diagnosis time.

Genuine Toyota converter prices by generation

Toyota catalogs the converter as part of a larger assembly: an “exhaust manifold converter sub-assembly” bolted to the head, a “front pipe” that carries a converter under the car, or both. Which one your car needs depends on engine, emissions certification and VIN. The list prices below come from an online Toyota parts dealer’s catalog and are shown only to illustrate the range.

Across the 2004, 2008, 2015 and 2020 listings we checked, list prices ran from about $495 for a manifold converter to about $3,435 for a front pipe assembly. Dealers often sell below MSRP, and labor is extra. Confirm the part number with your VIN before ordering; numbers that look alike can belong to different engines or emissions packages.

Why quotes for the same car vary so much

• Part type. A genuine Toyota assembly can cost several times an aftermarket direct-fit unit. See OEM vs aftermarket converters and CARB rules.
• Where the converter sits. A manifold converter on the engine takes different labor than a bolt-in front pipe.
• Engine. A V6 has a converter per bank. P0420 points at Bank 1 only, so ask why if a shop proposes replacing both sides.
• Where you live. In California, New York, Colorado and Maine, an aftermarket converter must carry a CARB Executive Order, which removes the cheapest options.
• Labor rate. Dealer, independent shop and mobile mechanic rates differ.

Check the warranty before you pay anything

Federal rules require the converter, the engine computer and the diagnostic system to be covered for 8 years or 80,000 miles, whichever comes first. Oxygen sensors are only covered for 2 years or 24,000 miles federally. California-certified cars can carry longer terms. If your Camry is anywhere near those limits, have a Toyota dealer check the VIN and in-service date before you approve an independent repair, because paying elsewhere first can complicate a claim.

How to read a P0420 quote

1. Ask what test results led to the recommendation: leak check, fuel trims, sensor response, catalyst monitor data.
2. Ask whether the converter is OEM or aftermarket, and for its brand and part number.
3. In a CARB-rule state, ask for the CARB Executive Order number on the part.
4. Ask whether sensors, gaskets and hardware are included or extra.
5. Ask what happens if the code returns within the parts warranty.

A shop that can answer those questions has probably done the diagnosis. A quote for a converter with no test results is a guess with a price on it.

Ways to avoid paying twice

The most expensive P0420 outcome is a second converter. That happens when the first repair ignored the cause: oil burning on a 2.4L 2AZ-FE, a misfire, or a leak that keeps fooling the rear sensor. It also happens when a part not built for the engine cannot store enough oxygen to satisfy Toyota’s monitor. Fix the cause, use a correct part, then drive until the catalyst monitor completes before you book an inspection. Our page on testing the A/F and O2 sensors covers the checks that keep a good converter from being condemned.

Start with the full P0420 code on a Toyota Camry guide for causes, the diagnosis flow and notes by engine.