P0455 Code: Jeep Cherokee (2019-2023) - Causes, Symptoms & Fixes

Diagnostic guide for OBD-II code P0455 on 2019-2023 Jeep Cherokee

Important data note

• NHTSA data you provided shows: No owner complaints for this exact make/model/year/issue; No recalls found in the NHTSA database.
• Because there are no recalls or complaint counts to draw from in this dataset, this guide relies on standard EVAP system knowledge and typical repair practices for vehicles of this family. Prices and scenarios are representative ballparks for 2025 and may vary by region, dealer vs. independent shop, and vehicle trim.

Code meaning and severity

• Code: P0455
• Full definition: Evaporative Emission Control System Large Leak Detected (gross leak/large leak)
• What it means: The vehicle’s evaporative emission control system detected a significant leak in the EVAP system. The leak is large enough that the on-board diagnostic monitor cannot seal or maintain expected system pressure during normal operation and self-tests.
• Severity and symptoms you may notice:
  • Check Engine Light (CEL) is on
  • Possible fuel odor around the vehicle or near the fuel filler area
  • Possible minor drop in fuel economy or more frequent fuel-system self-tests
  • In some cases, no obvious symptoms beyond the CEL and an EVAP test readiness not set

Common causes on Jeep Cherokee (2019–2023)

Note: This section reflects typical EVAP system failure points seen in many modern Jeeps and similar FCA vehicles. Specifics can vary by engine/transmission and the EVAP layout used in Cherokee.

• Gas cap issues
  • Loose, cracked, worn, or poorly sealing gas cap
  • Filler neck seal degradation
• EVAP hoses and clamps
  • Cracked, collapsed, or disconnected hoses between the fuel tank, canister, purge valve, and vent valve
  • Damaged or missing vacuum lines or vacuum hose clamps
• Charcoal canister (evaporative canister)
  • Cracked, saturated, or contaminated canister
  • Canister damage or internal rupture
• Purge valve (EVAP purge solenoid) or vent valve
  • Stuck open or closed
  • Electrical fault or wiring harness corrosion
• EVAP system leaks
  • Cracks or leaks in the fuel vapor lines, filler neck, or near the canister
  • Leaks that develop with temperature or pressure (pressurized leak points)
• Sealed/blocked paths
  • Restricted vent path or clogged purge/vent valves
  • Faulty pressure sensor or monitor wiring affecting leak detection
• Less common but possible
  • Fuel tank integrity issues (rare but possible) or near-tank hoses rubbing through
  • After-tank components or service port leaks

Symptoms to expect (practical observations)

• Check Engine Light illumination
• Smell of gasoline around the vehicle or fuel filler area
• Possible rough idle or drivability changes are uncommon with P0455; the primary symptom is the EVAP leak
• Emissions test failure in some jurisdictions due to failed EVAP test
• Owner may notice a hissing sound near fuel system in some chassis conditions (less common)

Diagnostic steps (step-by-step approach)

Note: If you’re not comfortable performing these, a professional diagnostic with a smoke test is recommended.

A. Initial check (easy fixes often resolve P0455)

• Inspect gas cap: tighten to 3 clicks; inspect for cracks, wear, or looseness; replace if suspect.
• Inspect visually accessible EVAP hoses and connections:
  • Look for cracked, loose, or rubbed hoses around the engine bay and near the fuel tank area
  • Check clamps for corrosion and tightness
• Check for any obvious signs of fuel odor inside the cabin or under the car

B. Scan data and freeze-frame

• Use a capable OBD-II scanner to verify P0455 is current (not pending) and check related P-codes
• Review EVAP-related live data:
  • EVAP system pressure sensor readings (if present on the Cherokee’s configuration)
  • Purge valve/solenoid status and duty cycle
  • Readiness monitors (EVAP) status
• Note any codes that often appear with P0455 (e.g., P0442 small leak, P0440 general EVAP fault)

C. Targeted tests

• Visual and mechanical test
  • Recheck all EVAP hoses for cost-effective fixes (tighten clamps, replace cracked hoses)
  • Inspect the filler neck for damage or misfit
• Smoke test (highly effective)
  • A professional-grade smoke test with a smoke machine is the most reliable way to locate large leaks in the EVAP system (hoses, canister, purge/vent valves, filler neck, and tank connections)
  • Look for smoke emanating from any EVAP components or joints
• Component-specific checks if no obvious leak found
  • Purge valve (solenoid): test operation (engine off vs. on) and listen for click; measure electrical resistance; verify voltage with key-on; verify purge flow when commanded
  • Vent valve: ensure proper venting when commanded and verify valve operation
  • Charcoal canister: inspect for cracks or saturated odor; difficult to test but inspect location and lines for damage
• Pressure/diagnostic test
  • If equipped, perform an EVAP pressure test per service information for the Cherokee. Some testers can pressurize the system to locate leaks more precisely than a simple visual check
• Fuel system integrity check
  • Inspect fuel lines from tank to canister for kinks, cuts, or crushed sections
  • Check for fuel leaks around the filler neck and underbody area

D. Confirm findings

• If a cap or hose is the fix, clear the code and drive to clear monitor(s)
• If a component is replaced, clear codes and re-test to ensure the EVAP monitor passes
• If leak remains after standard checks, expect to replace the responsible EVAP component (e.g., purge valve, vent valve, canister, or a section of hose)

Related codes (for context)

• P0440: Evaporative emission system malfunction
• P0442: Evaporative emission system leak detected (small leak)
• P0450–P0459: Various EVAP-related fault codes
• P0456: Evaporative emission system very small leak (sometimes used alongside P0455 to indicate varying leak severity)
• P0457: EVAP system leak detected (fuel cap removed) – varies by vehicle
  Note: These are common EVAP family codes and may appear alone or with P0455 depending on the vehicle’s self-test results.

Repair options and 2025 price ranges (Jeep Cherokee 2019–2023 context)

Prices vary by region, labor rate, and exact part. The ranges below reflect common parts and labor in the U.S. in 2025 dollars.

• Gas cap replacement
  • Parts: ~$10–$40
  • Labor: minimal (if DIY, $0; at shop, $50–$150)
  • Typical total: $10–$190 depending on cap price and labor
• EVAP hoses and clamps (short hoses, easy fixes)
  • Parts: $20–$100
  • Labor: $60–$180
  • Typical total: $80–$280
• EVAP purge valve (solenoid) replacement
  • Parts: $40–$150
  • Labor: $100–$250
  • Typical total: $140–$400
• EVAP vent valve replacement
  • Parts: $30–$120
  • Labor: $100–$250
  • Typical total: $130–$370
• Charcoal canister replacement
  • Parts: $150–$350
  • Labor: $150–$500
  • Typical total: $300–$850
• Fuel filler neck or related line replacement
  • Parts: $80–$350
  • Labor: $150–$350
  • Typical total: $230–$700
• EVAP system diagnostic and smoke test at a shop
  • Diagnostic fee: $80–$150 (some shops apply diagnostic to overall repair bill)
  • Smoke testing add-on: often included in diagnostic or $60–$120 if separate
• Total project costs (typical scenarios)
  • Simple fix (gas cap or minor hose/clip): $50–$250
  • Moderate fix (hose/clamp and/or purge/vent valve): $200–$600
  • Major fix (canister, tank line, or multiple components): $400–$1,200 or more

DIY vs professional

• DIY-friendly options (if you’re comfortable working around the fuel system)
  • Tightening or replacing a suspect gas cap
  • Inspecting exposed hoses for obvious cracks, disconnections, or signs of wear and re-securing clamps
  • Replacing simple hoses or clamps if you identify a clear damaged section
  • Clearing a simple P0455 after fixing the cap or a leak and confirming the monitor passes on a road test
• When to go pro
  • There is a persistent P0455 after correcting a gas cap and obvious hose issues
  • You smell fuel or notice a strong fuel odor
  • You cannot locate the leak visually
  • The EVAP system is covered by a warranty on your vehicle or you don’t have access to a smoke machine
  • You want definitive leak location and a reliable fix quickly; a professional using a smoke machine and proper diagnostic tools will locate hidden leaks more efficiently
• Practical tips
  • Have a shop perform a smoke test if the leak isn’t obvious
  • Request a pre-repair diagnostic and an itemized estimate
  • If the vehicle is under warranty, check coverage for EVAP components

Prevention and maintenance

• Regularly check and replace the gas cap as needed; use the correct fuel cap for your Cherokee model
• Inspect the EVAP system during routine maintenance when you notice any fuel odor or a CEL
• Avoid rough handling around the fuel system area; protect hoses from heat and road debris
• Use high-quality fuel and maintain proper fuel system health to minimize stress on EVAP components
• If you tow or carry heavy loads, periodic inspection of underside EVAP lines is prudent due to potential hose chafing

Data limitations reminder

• Based on the provided NHTSA data, there are no listed recalls and no owner complaints for this specific combination. This means the guide relies on general EVAP knowledge and common practice for this code, not on vehicle-specific recall or complaint history. If you have access to your own vehicle’s service history or factory service bulletins (TSBs) for your exact Cherokee model and year, those documents could provide additional, model-specific steps or fixes not reflected here.