How to Replace the Fuel Cap on a 2019 GMC Canyon (Fix EVAP Leak & Check Engine Light)
Step-by-step fuel cap install with required tools/parts, safety tips, and what to do if the CEL returns
How to Replace the Fuel Cap on a 2019 GMC Canyon (Fix EVAP Leak & Check Engine Light)
Step-by-step fuel cap install with required tools/parts, safety tips, and what to do if the CEL returns
🔧 Canyon - Fuel Cap Replacement
Replacing the fuel cap is usually a quick job that helps prevent fuel vapor leaks (EVAP leaks) that can trigger a check-engine light. On your Canyon, a worn seal or a cap that won’t click tight is the most common issue.
Difficulty Level: Beginner | Estimated Time: 0.1-0.2 hours
⚠️ Safety & Precautions
- 🧯 Do this outdoors or in a well-ventilated area; fuel vapors are flammable.
- 🚭 No smoking, sparks, or open flames near the fuel door.
- 🧤 Avoid skin/eye contact with fuel; wear gloves and safety glasses.
- 🔌 Battery disconnect is not required.
🔧 Required Tools
You'll need the following tools for this repair:
- Nitrile gloves
- Safety glasses
- Clean shop towel
- Flashlight
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Fuel cap (EVAP-sealed, correct for Canyon) - Qty: 1
📋 Before You Begin
- Park on level ground, shift to Park, and shut the engine off.
- Wait 1-2 minutes before opening the cap if you just drove the truck.
- Open the fuel door and have a clean shop towel ready.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Open the fuel door
- Open the fuel door on the driver side rear quarter area.
- Use a flashlight if visibility is poor.
Step 2: Remove the old fuel cap
- Turn the cap counterclockwise until it releases, then remove it by hand.
- If the cap is tethered, let it hang by the tether (the small strap that keeps you from losing it).
Step 3: Inspect and clean the filler neck sealing surface
- Use a flashlight to look at the rim (the round sealing surface) of the filler neck.
- Wipe the rim with a clean shop towel.
- Tip: Dirt here can cause EVAP leak codes.
Step 4: Install the new fuel cap
- Place the new cap onto the filler neck and turn it clockwise by hand.
- Tighten until you feel/hear it click (typically several clicks). This is the cap’s built-in clutch that sets proper tightness.
- Do not use tools to tighten the cap.
Step 5: Close the fuel door
- Close the fuel door firmly by hand.
- Use a shop towel to wipe any fuel residue if present.
✅ After Repair
- Start the engine and confirm there is no fuel smell around the fuel door area.
- If you had a check-engine light for an EVAP leak, it may take a few drive cycles to turn off on its own. A scan tool can clear it immediately, but only if the cap/seal was the real cause.
- If the light returns, the issue may be the filler neck seal, purge/vent system, or an EVAP leak elsewhere.
💰 DIY vs Shop Cost
Shop Cost: $40-$120 (parts + labor)
DIY Cost: $15-$45 (parts only)
You Save: $25-$75 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.1-0.2 hours.
🎯 Ready to get started?
HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.

















