Emissions code · Boston area, Massachusetts
P0420 repair cost in Boston
P0420 means catalytic converter not working well (bank 1). In the Boston area, Massachusetts, the most common fix, catalytic converter replacement, has a typical range of $450 to $2,400.
Wide range: this job varies a lot. Itemize your quote for a better answer.
How this range is built
| Part of the job | Low | High |
|---|---|---|
| Parts | $300 | $1,900 |
| Labor: 1.2 to 2.5 hours × $125 to $175 an hour | $150 | $438 |
| Fees: shop supplies, disposal, diagnostics | $0 | $40 |
| Total, rounded | $450 | $2,400 |
The hourly rate is the BLS Occupational Employment and Wage Statistics, May 2025 average pay for this trade in Boston, $31.54 an hour, times 4 to 5.5 to cover what a shop bills (overhead, tools, insurance, profit). Parts are a band from budget aftermarket to the manufacturer part. In California and New York, parts cost more because those states require a California-certified converter. Full method.
Not a repair shop, estimates only. Typical range, estimate. Not a quote. Your car, parts and shop change the number.
Why Boston is different
The parts cost about the same everywhere. The labor rate is what changes. Auto technicians in the Boston area, Massachusetts earn an average of $31.54 an hour, so a shop there bills roughly $125 to $175 an hour. That moves this repair's total, and the range above already includes it.
Same repair in other areas
| Area | Typical range, estimate |
|---|---|
| New York City area | $560 to $3,125 |
| Los Angeles area, California | $590 to $3,325 |
| Chicago area, Illinois | $430 to $2,350 |
| Houston area, Texas | $420 to $2,325 |
| Dallas-Fort Worth area, Texas | $420 to $2,325 |
| Phoenix area, Arizona | $430 to $2,325 |
| Atlanta area, Georgia | $430 to $2,350 |
| Miami area, Florida | $420 to $2,325 |
| Seattle area, Washington | $450 to $2,375 |
What the code means, causes and what to check first are on the P0420 page.
Not a repair shop, estimates only. Typical range, estimate. Prices updated October 2026.