Proficient Auto — Car Care with a Conscience
Ignition System

Mobile Spark Plug Replacement & Repair

Misfire codes, rough idle, or a check engine light that comes back? We replace spark plugs and ignition coils at your driveway — with OEM-spec parts gapped to factory specs and torqued correctly (over-torquing aluminum heads is how plugs strip out).

Get a spark plug quote919-675-AUTO
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Why this is a perfect mobile job

Spark plug replacement requires no lift, no special facility, and 90 minutes of focused work. We come to you, replace plugs with OEM-spec iridium or platinum units, replace any failed coils, clear the codes, and road-test for misfires before leaving. You don't lose a day at the shop.

We torque every plug to spec with a calibrated wrench. Most modern engines (especially Honda, Ford EcoBoost, BMW, Audi) have aluminum heads where over-torquing pulls threads and turns a routine job into an expensive head repair. We don't take shortcuts.

When you actually need new plugs

  • Manufacturer interval: usually 60,000 mi (copper), 100,000 mi (platinum), or 100,000–120,000 mi (iridium)
  • Active misfire code (P0300–P0312) — we test the coil first, then the plug
  • Rough idle, hesitation under load, or worse fuel economy
  • Hard starting, especially cold or in rain
  • Came up on a pre-purchase inspection as overdue
Common questions

Frequently asked questions

How much does mobile spark plug replacement cost?
Spark plug pricing depends on cylinder count and engine layout — 4-cylinder engines are quicker than transverse V6s with buried rear-bank plugs. If you need ignition coils too, we test each coil first and only quote the ones that have actually failed. Firm written quote before any work starts.
How often should spark plugs be replaced?
Most modern vehicles use iridium plugs rated for 100,000–120,000 miles. Direct-injection turbo engines (Ford EcoBoost, Audi/VW 2.0T, BMW N20/B58) often need plugs sooner — 60,000–80,000 miles — because higher cylinder pressures wear them faster. Check your owner's manual or ask us.
Can a bad spark plug damage my catalytic converter?
Yes. A misfiring cylinder dumps unburned fuel into the exhaust, which superheats and can destroy the catalytic converter — an expensive part on most cars. If you have a misfire code (P0300–P0312), don't keep driving on it. Get it diagnosed this week.
Do you replace ignition coils too?
Yes — usually at the same visit. We test each coil with a scope or scan-tool misfire counter and only replace the failed ones, not the whole set, unless they're all original and high-mileage. You don't need to throw money at parts you don't need.

Ready to skip the shop?

Get a free, no-pressure quote — usually within the hour. We come to your home, office, or wherever the car is sitting.

Get a spark plug quote 919-675-AUTO