Quick answer: Spark Plug Replacement on a 2015–2020 Chevrolet Tahoe is rated Advanced and takes about 1-3 hours. You'll need 4 tools for this job, and parts cost about $115. This guide walks you through the full job step by step, including the mistakes to avoid.
| Part Name |
Part Number |
Price |
Buy |
| Correct spark plug set for 2015-2020 Chevrolet Tahoe; verify engine, heat range, gap, and VIN fitment |
— |
$115.00 |
|
| Coil-boot seals or ignition coils only if inspection finds damage Optional |
— |
$35.00 |
|
About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.
💡 Pro tip: Order all parts at once to save on shipping
Step-by-Step Instructions
Follow these steps carefully
1
Confirm engine and plug fitment
Confirm your 2015-2020 Chevrolet Tahoe's engine: the standard 5.3L EcoTec3 V8 (L83) and the RST's 6.2L (L86) both take the same plug — eight AC Delco 41-114 iridium plugs, pre-gapped to 0.040 inches at the factory. Do not substitute copper or single-platinum plugs: the EcoTec3's direct injection and Active Fuel Management are calibrated for this iridium plug's heat range. Scan for misfire codes (P0300-P0308) before ordering and note the cylinder; on these trucks the number 8 plug at the rear of the passenger bank works the hardest and is the usual first failure.
2
Cool and expose the plugs
Let the Tahoe cool completely — aluminum heads and hot plug removal strip threads. Twist each boot to break it free, then pull the wires off with plug-wire pliers — never by the wire.
3
Remove the coils
Unbolt any coils in your way and lay the plug wires aside in firing order so nothing gets crossed on reassembly. Use a 5/8-inch (16mm) spark plug socket with the rubber insert so the plug comes out captured.
🔧 Mechanic's note — Ray Delgado
The heat shields matter more than they look — I've seen exhaust heat cook an unshielded plug boot in months, so if one crumbles in my hand I replace it; it's a cheap part protecting an expensive misfire diagnosis.
4
Remove and install plugs
Remove each old plug and hold it next to the new AC Delco 41-114: identical reach, tapered seat and iridium construction. The factory 0.040-inch gap should be verified with a wire-type gauge, but never pry on the iridium center electrode — GM's guidance is to discard any plug that arrives out of spec rather than risk fracturing the tip. Thread each new plug in by hand for several turns until it seats squarely, then torque to 11 ft-lb (132 in-lb), the book spec for these tapered-seat plugs; confirm in your owner's manual. Install them dry — the coated shell needs no anti-seize, which would corrupt the torque reading.
🔧 Mechanic's note — Tom Becker
GM says I should discard an iridium plug that arrives out of spec — I never try to close the gap, because that fine-wire center electrode fractures if I lever on it, and a cracked tip turns a new plug into a future misfire.
5
Grease the boots and verify
Smear dielectric grease inside each plug boot only — never on the plug itself — to prevent moisture tracking and ease the next service. Push each wire back onto its plug and reinstall the coil bolts. Start and confirm a smooth idle with no flashing check-engine light.
🔧 Mechanic's note — Tom Becker
The steady-cruise test drive is where cylinder deactivation engages for me — that's when I've learned a weak wire shows up, and idling in the driveway won't load it the way deactivation does.
All Done!
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
- • Using the wrong plug or assuming a pre-gapped plug needs no verification
- • Blowing debris into an open cylinder or plug well
- • Cross-threading a plug or tightening it without a torque wrench
- • Overusing anti-seize or dielectric grease on the plug threads
- • Mixing coil connectors or ignoring a misfire after reassembly
