Same job at other shop types (everything else as set above): Independent shop (~$100/hr) $182–$347 · Chain shop / franchise (~$120/hr) $200–$372 (the headline above) · Dealership (~$175/hr) $252–$441. Each figure applies that shop type's hourly labor rate (market estimates, shown above) to the calculator's own hours and parts assumptions. It is modeled, not a quote.
Check a quote against these ranges
This sets your number beside published ranges and owner-written bills. It is not a verdict: ask the shop what the quote includes (parts grade, labor hours, fees, tax). It runs in your browser and nothing you type is sent anywhere.
How the price estimate was built
What it shows: Our default range is $200 to $372; 3 of 4 published ranges overlap it.
How serious did it get for owners?
5% of the 2,782 complaints report a tow, the most common serious outcome; the other outcomes counted below are rarer, and an owner can file without mentioning one.
What it shows: Towed is the largest at 139, followed by Fire reported at 16; the smallest shown is Injury reported at 8.
Counts below are complaints filed with NHTSA, not failure rates: a longer bar means more owners reported it.
Is your car affected?
What it shows: The most common band for complaints about this repair is 50,000-100,000 (53%). The biggest difference from all complaints is under 50,000: 18% against 60%.
What it shows: The most common band for complaints about this repair is 6-9 years (56%), against 23% for all complaints: the biggest difference between the two.
Is it urgent, and what do owners notice first?
2,782 owner complaints name this part.
What owners describe. Warning light: 60%; Stalled or lost power: 21%.
Owners most often describe "warning light", in 60% of these complaints.
Which trouble codes do owners report?
P0302 Cylinder 2 Misfire Detected is the largest group at 57, out of 2,782 complaints.
The code owners quote most is P0302. Read your own code from a scan and give the shop the exact code, not only "the light is on".
What do owners say it led to?
Among the 2,782 owner complaints naming this part, owners most often say engine damage followed.
What owners say happened after the problem. Engine damage: 129 (5%); Loss of power: 76 (3%); Stalled while driving: 12 (0%).
If your car shows the signs above, get it checked before it gets as far as engine damage.
Which other parts do owners name in the same complaint?
Among the 2,782 owner complaints naming this part, ignition coil is named in 23% of them, more than any other part.
Owners name the ignition coil most often in the same complaint, which is not proof that one caused the other. Ask the shop whether it checked the ignition coil too, so you are not quoted twice for one visit.
How fast were owners driving when it happened?
55 mph or faster is the largest group at 43%, out of 1,114 complaints.
Owners reported it most often at highway speed. Tell the shop what speed it happens at, because that narrows the diagnosis.
Which model years show up most in the complaints?
2017 is the most common model year in 2,782 complaints naming this part (28%); 2 model years account for 51%.
What it shows: 2017 is the largest at 775 (28%), followed by 2015 at 257 (9%); the smallest shown is 2025 at 13 (0%).
Is this repair covered by an emissions warranty?
Federal rules require carmakers to cover the catalytic converter, the emissions computer and the onboard diagnostic system for 8 years or 80,000 miles, and any part whose failure fails an emissions test for 2 years or 24,000 miles; California requires 3 years or 50,000 miles on every emission part.
| Warranty | Covers | Length |
|---|---|---|
| California, all emission parts | All emissions-related parts | 3 years or 50,000 miles |
| California, high-cost parts | Specific high-cost emission parts listed in the owner manual | 7 years or 70,000 miles |
| Federal, basic | Any part that causes an emissions failure | 2 years or 24,000 miles |
| Federal, extended | Catalytic converters, electronic emissions control unit (ECU), onboard emissions diagnostic device or computer (OBD) | 8 years or 80,000 miles |
Which engine sizes show up most in complaints about this part?
Among 2,750 owner complaints about this part where the VIN identifies the vehicle, 26% involve engines of under 1.6 L, against 11% of complaints about all the parts we track.
What it shows: 1.6 to 2.0 L is the largest at 37%, followed by Under 1.6 L at 26%; the smallest shown is Over 5.0 L at 4%.
What do emissions repairs cost?
Among 46,033 California vehicles repaired to pass a Smog Check in 2025, 39.1% cost over $650 to fix and the average bill was $757.
What it shows: Over $650 is the largest at 39.1%, followed by $1 to $100 at 13.1%; the smallest shown is $501 to $650 at 8.4%.
Do spark plug replacement problems track gallons of motor gasoline burned per resident per year across states?
Gallons of motor gasoline burned per resident per year (SEDS, transportation)
Complaints against what the makes sold would predict (1.0× = expected)
left map: lower to higherright map: green fewer complaints than expected, red morefurthest from the pattern: CO, IA, LA, NE, NH, NJ, NM, NV, OH, RI, TX, WVfewer than 10 complaints
This describes states, not any one car, and it does not show that the left measure produces the right one.
Every state with 10 or more complaints, most over-reported first: state, gallons of motor gasoline burned per resident per year (seds, transportation), complaints against expected, complaints filed.
- RI 326 · 1.83× · 13
- NE 442 · 1.59× · 20
- LA 463 · 1.44× · 53
- OH 391 · 1.32× · 151
- KY 475 · 1.31× · 51
- TN 474 · 1.26× · 80
- MS 557 · 1.24× · 26
- ME 458 · 1.23× · 15
- KS 448 · 1.22× · 28
- WV 407 · 1.22× · 21
- NC 464 · 1.19× · 121
- MO 506 · 1.16× · 64
- WI 409 · 1.14× · 55
- GA 431 · 1.13× · 122
- PA 329 · 1.11× · 119
- IL 319 · 1.11× · 113
- AL 629 · 1.10× · 50
- VA 450 · 1.08× · 101
- DE 464 · 1.04× · 12
- MN 410 · 1.04× · 40
- AR 485 · 1.03× · 24
- UT 371 · 0.99× · 22
- SC 508 · 0.97× · 50
- IN 418 · 0.95× · 51
- MI 425 · 0.94× · 98
- OR 322 · 0.94× · 25
- WA 318 · 0.94× · 54
- MA 348 · 0.93× · 51
- CA 318 · 0.93× · 262
- FL 402 · 0.92× · 207
- OK 459 · 0.90× · 29
- NH 488 · 0.89× · 13
- TX 469 · 0.88× · 218
- IA 461 · 0.87× · 19
- AZ 387 · 0.83× · 52
- MD 369 · 0.81× · 54
- CO 375 · 0.80× · 39
- NY 257 · 0.77× · 94
- NJ 370 · 0.76× · 58
- NV 353 · 0.75× · 18
- NM 431 · 0.68× · 10
What it shows: States with more gallons of motor gasoline burned per resident per year (seds, transportation) tend to sit higher on the chart across 41 states: a pattern in the data, not proof of cause.
- A weak hint, not a firm finding: about 1 in 5 or more patterns this clear turn out to be false alarms. Weak spot: hold workers who drive alone to work equal and the gallons of motor gasoline burned per resident per year pattern disappears, so it may be mostly that factor.
Are the parts for this repair getting more expensive, or only the labor?
The federal producer price index for new spark plugs and other complete engine electrical equipment rose 33.5% from December 2019 to August 2026, while the consumer price index for motor vehicle repair, labor and parts together, rose 55.2% (BLS, national).
What it shows: New electrical and electronic engine equipment parts is the largest at +57.0%; the smallest shown is All motor vehicle parts at +17.4%.
Has this part been recalled abroad on cars that may share it?
Manufacturers filed 1 foreign recall campaigns that name spark plug with NHTSA since 2015; the latest, from Toyota Motor Corporation in 2022-01. These are recalls abroad, and they apply to U.S. cars only if the same model is sold here.
| Filed | Manufacturer | Foreign recall no. | What the filing says |
|---|---|---|---|
| 2022-01 | Toyota Motor Corporation | 003 | With a 9NR engine containing ignition coils, which are used to raise the voltage of the electricity from the vehicle battery to ignite the spark plugs. |
What do owners who wrote down a dollar amount say they paid?
Among 20 NHTSA owner complaints about this part that name one component and one repair, the middle dollar amount an owner wrote was $2,300, with a quarter at $905 or less and a quarter at $3,600 or more; these are selected owner reports, not a representative price.
| Measure | Amount or count |
|---|---|
| A quarter of owners wrote this much or more | $3,600 |
| Middle amount owners wrote | $2,300 |
| A quarter of owners wrote this much or less | $905 |
| All complaints naming the part with any dollar amount, before the filter | 124 |
| Complaints with one component, no repeat or tow wording, and a dollar amount | 20 |
If this part was recalled, is the repair free?
Federal law (49 U.S.C. 30120) requires a maker to fix a recalled defect without charge for cars first bought within 15 calendar years (tires within 5), and NHTSA lists 1 recall campaigns for parts matched to a spark plug replacement since model year 2015, covering about 7 vehicles.
| Rule or count | What it says |
|---|---|
| Age limits | The free-remedy duty does not apply to a car first bought more than 15 calendar years, or a tire first bought more than 5 calendar years, before the recall notice. |
| Failure to fix | A repair not done adequately within 60 days of presentation is prima facie evidence of failure to repair within a reasonable time; the maker must then replace the vehicle or refund the purchase price less depreciation. |
| Free remedy | A maker must fix a recall defect without charge. |
| NHTSA recalls matched to a spark plug replacement since model year 2015 | 1 recall campaigns covering about 7 vehicles |
Does my engine design make this repair more likely?
EPA's Automotive Trends data show turbocharged gasoline engines in 44.4% of new gasoline cars in model year 2024 against 1.4% in 2005, and turbo engines run hotter and wear spark plugs and coils sooner (sales-weighted national shares).
| Model year | Turbocharged | Direct fuel injection | Average cylinders | Average horsepower |
|---|---|---|---|---|
| 2000 | 1.2% | 0.0% | 5.7 | 181 |
| 2005 | 1.4% | 0.0% | 5.8 | 209 |
| 2010 | 2.6% | 8.3% | 5.3 | 214 |
| 2014 | 13.8% | 37.8% | 5.1 | 231 |
| 2018 | 29.6% | 60.5% | 5.0 | 239 |
| 2021 | 31.8% | 72.1% | 5.0 | 251 |
| 2024 | 44.4% | 79.5% | 4.7 | 247 |
Is it recalled or covered?
| Recall number | Vehicles | Cars recalled | What the recall says |
|---|---|---|---|
| 21V-124 | Mercedes-Benz AMG CLA45 2020 | 7 | Engine damage may result in an engine stall, increasing the risk of a crash. |
A bulletin is a repair procedure a maker sends its dealers, not a safety defect: if your maker is listed, ask the dealer whether one covers your car and quote its number.
| Maker | Vehicles | Bulletin number | Date | What it says |
|---|---|---|---|---|
| Jeep | Grand Cherokee L 2026–2027; Grand Cherokee 2026–2027 | 66D Combo Rev1 | Jul 27, 2026 | Customer satisfaction notification north america Spark Plugs Reference: 66D The spark plugs insulator on approximately 48,000 of the above vehicles may break due to excessive cylinder pressure. |
| Jeep | Grand Cherokee 4xe 2026; Grand Cherokee 2026 and 1 more | 66D Dealer | Jul 22, 2026 | Spark Plugs The spark plugs insulator on approximately 48,000 of the above vehicles may break due to excessive cylinder pressure. |
| Jeep | Grand Cherokee L 2026; Grand Cherokee 2026 | 112536 | May 27, 2026 | Claim submission for hurricane spark plug. |
| Jeep | Renegade 2022–2025; Compass 2022–2025 | 09-026-25 | Sep 3, 2025 | Not applicable to vehicles built for US market. |
| Land Rover | Range Rover 2023–2025; Range Rover Sport 2023–2025 | SFCC_FEB2025_47 | Feb 14, 2025 | MIL on, misfire, or fuel smell after spark plug service. |
| Dodge | Challenger 2023 | 09-016-24 | Jul 17, 2024 | Spark Plug Re-Gap to Resolve Misfire Symptoms Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): P0300 - Multiple Cylinder Misfire. |
23 more bulletins name this part; the car finder at the top checks yours, and the NHTSA bulletin file linked below lists them all.
What do owners say?
4 complaints quoted word for word, each with its NHTSA number.
That statement couldn't be more INACCURATE a few weeks ago I was told I needed a new head/spark plugs and the block was warp and I would not be able to drive it until it was repaired (a $5k job).
Another $980 a couple weeks ago for battery , spark plugs , computer software update etc.
About $1,000 was spent on "cleaning" the engine and replacing the spark plugs and other effected components, with no improvement on oil consumption.
My car is currently at dealers getting looked at and they recommended changing my fuel injector and spark plugs, which they completed ($2,000) and I AM STILL having issues.!!!
Check your car
Our calculator's default spark plug replacement cost is $200–$372 for four iridium plugs, parts plus labor at $120 an hour. Plug type, how many cylinders your engine has and the shop you choose move that number.
What does the spark plug price cover?
The estimate covers one plug per cylinder and the labor to swap them, at the hourly rate for the shop type you pick. It does not cover anything the job uncovers: a cracked coil boot, a seized plug that has to be extracted, or a leaking valve cover gasket that is oil-fouling the plugs.
Taxes, shop fees and a diagnostic charge are also outside the range. Some shops waive the diagnostic fee if you approve the repair, so ask.
How much do plug type, cylinders and shop change the price?
Plug type is the biggest lever after cylinder count. Here are the calculator's ranges, changing one setting at a time from the default.
| Setting | Estimate |
|---|---|
| Default: 4 iridium plugs, $120/hr | $200–$372 |
| 3 cylinders | $178–$317 |
| Copper plugs (every 30k miles) | $136–$208 |
| Platinum plugs (every 60k miles) | $160–$272 |
| Independent shop (about $100/hr) | $182–$347 |
| Dealership (about $175/hr) | $252–$441 |
Copper is cheapest now but is replaced twice as often as platinum, so the lower price is not always the lower cost. Use the plug type in your owner's manual; a different type than the engine was built for is not a saving.
What does the estimate leave out?
It is a range for a typical engine, not a quote for yours. Engines where the plugs sit under an intake manifold or behind other parts take more labor than a four-cylinder with plugs on top. Larger engines with more cylinders cost more than the default.
If a quote lands well above the range for your plug type and shop, ask what is being added before you pay. The next step is to enter your setup in the calculator and take that range with you.
Frequently asked questions
Can I replace spark plugs myself?
Many owners do on easy-access engines, and it saves the labor line. Gap and torque matter, and a cross-threaded plug can ruin a cylinder head, so skip it if the plugs are buried.
Should I replace the ignition coils at the same time?
Only if a coil is actually failing. Ask the shop to test them rather than replacing them by default.
Sources
Data shown on this page
- NHTSA owner complaint file (2015-2019 · 2020-2024 · 2025-2026) downloaded 2026-10-05
- NHTSA recall file downloaded 2026-10-05
- NHTSA service bulletin file (2015-2019 · 2020-2024 · 2025-2026) downloaded 2026-10-05
- U.S. Code of Federal Regulations, 40 CFR 85.2103, and the California Air Resources Board warranty fact sheet downloaded 2026-10-05
- NHTSA owner complaint files with VINs decoded by NHTSA vPIC data from 2025
- California Bureau of Automotive Repair, Smog Check Executive Summary Report 2025 data from 2025
- EIA State Energy Data System, motor gasoline consumption, joined to NHTSA owner complaints downloaded 2026-10-12
- BLS Producer Price Index, commodity data for motor vehicle parts (series WPU1412051426); BLS Consumer Price Index item SETD for the repair row downloaded August 2026
- NHTSA Office of Defects Investigation, Foreign Campaigns (filings under 49 CFR 579.11, public API) downloaded 2026-10-05
- 49 U.S.C. 30120 (Remedies for defects and noncompliance), text via Cornell Legal Information Institute; NHTSA recall campaigns data from 2026
- U.S. EPA, The 2025 EPA Automotive Trends Report (EPA-420-R-26-001) downloaded 2026-10
Terms: US government data, public domain.
Observed: records as filed; owner reports are unverified and are not failure rates. Rule: a published legal rule, not a measurement; whether it covers a given repair depends on the car and the facts. Derived: computed from the records; an association, not a cause.
What is our own estimate
The price range comes from our calculator's formula. Its parts prices, labor hours per job and shop-rate tiers are CalcScrape estimates, not a published price dataset. Checked against 4 established price guides on 2026-10-04: our default's midpoint is 17% below the middle of RepairPal's range ($288–$399). Price evidence grade A: 4 outside published ranges; the hours and parts prices behind the estimate are CalcScrape assumptions and have not been checked against repair invoices. Methodology