2016-2021 Honda Civic: Common Problems

Common Problems for 2016-2021 Honda Civic

Data snapshot

• Official recalls in NHTSA database: No recalls found for this model/year range.
• Owner complaints (from provided data): 1 record
  • Year: 2016
  • Component: transmission
  • Mileage: 25,911 miles
  • OBD Code: P0455
  • Description: Vehicle experiences fuel economy issues with code P0455. The transmission appears to be malfunctioning. Issue is intermittent, mainly during highway driving. Dealer unable to diagnose root cause after multiple visits.

Important note about the data

• This dataset contains a single complaint entry, which limits the ability to generalize about the entire 2016-2021 Civic population. No recalls are listed in the data provided. Use this guide as a data-informed starting point and supplement with your own vehicle history, service records, and up-to-date diagnostic work from a trusted shop.

What the data suggests about 2016-2021 Civics

• The only documented issue in this data set involves a 2016 Civic with a reported P0455 code and intermittent “transmission” concerns. P0455 is commonly associated with the EVAP (evaporative emissions) system, not a direct transmission fault. In practice, a driver may notice fuel economy changes or a check engine light, while a separate transmission symptom (shudder, slipping, harsh shifting) could be coincidental or related to another underlying fault.
• Since there are no recalls in the data, owners should rely on typical diagnostic steps, quality maintenance of the CVT (if equipped), and standard fuel system checks to address symptoms.

Understanding the primary items in the complaint

• P0455 (EVAP system gross leak)
  • What it means: A large leak detected in the EVAP system, which can cause the engine computer to illuminate the check engine light and affect fuel trims and fuel economy.
  • Common culprits: loose or cracked gas cap, EVAP hoses, purge valve, charcoal canister, vent valve, or the EVAP canister itself.
  • Potential impact: Reduced fuel economy, emissions readiness issues, possible rough idle or hiccups during startup if the leak is large enough.
• Transmission concerns (in the complaint)
  • In Civics from this era, many models use a CVT (continuously variable transmission). Symptoms often described by owners include shuddering, slipping, hesitation, or harsh shifts, especially during acceleration or cold starts.
  • Possible contributing factors (beyond a true mechanical failure): low or degraded CVT fluid (type and level), overheating, sensor or actuator issues, or a separate engine/fuel issue masking or mimicking true transmission behavior.

Practical diagnostic and troubleshooting guidance for owners

Start with the EVAP system

• Step 1: Check the gas cap
  • Ensure it is properly tightened and the seal is intact. Replace if you notice damage or persistent looseness.
• Step 2: Visual inspection
  • Look for cracked or disconnected EVAP hoses, cracked tubing, or signs of damage around the EVAP canister and purge valve.
• Step 3: Scan for codes and monitor fuel trims
  • If you have a scanner, note long-term fuel trim readings (LTFT) at idle and during light acceleration. Positive LTFT may indicate an EVAP or fuel delivery issue.
• Step 4: EVAP system test
  • A professional shop may perform EVAP leak testing (smoke test or diagnostic readouts) to locate a leak that isn’t obvious visually.
• Step 5: Address root cause
  • Gas cap replacement: often inexpensive and quick.
  • Leaky hoses, purge valve, or canister: costs vary (see 2025 cost estimates). Replacing a purge valve or suspected hoses is a common repair.

Assess the transmission (CVT) symptoms

• Step 1: Check transmission fluid (if applicable)
  • Many Civics with CVTs require a specific CVT fluid. Check level and condition if accessible; note that some CVTs are not serviceable via simple dipstick checks.
  • Look for metallic smell, dark color, or foamy appearance in the fluid.
• Step 2: Rule out engine-related causes
  • Misfires, fuel delivery problems, or sensors can mimic transmission symptoms. Ensure spark plugs, coils, MAF/MAP sensor, and fuel system are in good shape.
• Step 3: Consider CVT fluid service
  • If the fluid is old, degraded, or the vehicle has high mileage, a CVT fluid drain-and-fill (plus filter if applicable) can help reduce slipping or shudder in some cases.
• Step 4: Diagnostic testing
  • A professional scan tool can check CVT-related codes and sensor outputs (e.g., speed sensor signals, torque converter status, and transmission range sensor).
• Step 5: Escalation
  • If symptoms persist after maintenance, a transmission specialist or Honda dealer may evaluate for deeper CVT issues or internal wear.

Maintenance practices to prevent or reduce problems (2016-2021 Civics)

• EVAP/system health
  • Use quality fuel from reputable stations to reduce contaminants.
  • Promptly address any check engine light that appears, especially if it triggers P0455 or related codes.
  • Regularly inspect the gas cap and EVAP hoses during routine maintenance.
• Transmission/CVT health (if applicable)
  • Follow Honda’s recommended service intervals for CVT fluid changes (if specified for your model). Do not mix fluids; use the exact Honda CVT fluid called for by your owner's manual.
  • Avoid aggressive driving after a cold startup; this helps reduce transmission wear in some CVT designs.
  • Keep cooling systems in good condition; CVTs can overheat if the cooling system is compromised.
• General
  • Regular oil changes with the correct grade ensure engine performance and emissions systems function well, which indirectly affects fuel economy and transmission load.

Estimated costs for common 2025 repairs related to the observed issues
Notes:

• Prices vary by region, shop, and whether a DIY fix is feasible. The ranges below reflect typical U.S. market costs for 2025.
• Diagnostic steps are often charged separately if you don’t proceed with the repair.

EVAP system/P0455-related repairs

• Gas cap replacement
  • Parts: $5-$25
  • Labor: $15-$40
  • Total: roughly $20-$60
• EVAP hose/tube replacement
  • Parts: $20-$150
  • Labor: $60-$180
  • Total: roughly $80-$330
• EVAP purge valve replacement
  • Parts: $25-$150
  • Labor: $60-$120
  • Total: roughly $85-$270
• EVAP canister replacement
  • Parts: $300-$800
  • Labor: $150-$350
  • Total: roughly $450-$1,150
• EVAP system diagnostics (if needed)
  • Diagnostic fee: $80-$150 (waived by some shops if repair is performed there)

Transmission/CVT related (if Honda Civic CVT-equipped)

• CVT fluid drain and fill (recommended service interval)
  • Parts: $10-$60 (fluid cost)
  • Labor: $100-$200
  • Total: roughly $110-$260
• CVT fluid and filter service (if applicable)
  • Parts: $20-$100
  • Labor: $120-$250
  • Total: roughly $140-$350
• Transmission diagnosis (codes, test drive, sensor checks)
  • Diagnostic fee: $100-$150
  • If any repair is required afterward, diagnostic fee may be credited toward the repair cost at some shops
• Transmission repair or replacement (worst-case scenario)
  • Transmission rebuild/repair: $1,500-$3,500 (plus labor)
  • Transmission replacement (new or remanufactured): $2,500-$5,000+ (parts and labor)
  • Note: CVT replacement tends to be on the higher end; exact cost depends on model, availability of parts, and labor rates

What to do next if you own a 2016 Civic with similar symptoms

• Step 1: Get a diagnostic scan
  • Have a qualified shop pull codes and live data. Confirm whether P0455 is the only code or if there are related codes (fuel trims, misfire, transmission-related codes, etc.).
• Step 2: Inspect the EVAP system
  • Start with the gas cap and visible hoses; pursue a smoke test if leaks are suspected.
• Step 3: Evaluate transmission symptoms
  • Have the transmission fluid checked (if applicable) and the overall CVT health assessed. Request a test drive with the technician to reproduce symptoms.
• Step 4: Plan repairs with cost estimates
  • If the EVAP issue is found, consider the most likely repair: gas cap, then hoses/valve, then canister. If transmission symptoms persist after EVAP work, pursue CVT diagnostics before major component replacement.
• Step 5: Prevent future issues
  • Adhere to maintenance schedules, avoid high-load operation when the engine is cold, and address any warning lights promptly.

Data limitations and how to use this guide

• Only one 2016 Civic complaint is available in the provided data. This limits inference about the broader 2016-2021 Civic population.
• No recalls were listed in the provided data. If you’re experiencing problems, check current NHTSA listings and Honda service bulletins for any updates beyond this dataset.
• Use this guide as a starting point for troubleshooting with your mechanic, not as a definitive diagnosis for every vehicle.

Bottom line

• From the data provided, the sole documented issue involves a 2016 Civic with a P0455 EVAP-related concern and self-reported transmission-like symptoms. In practice, P0455 is typically EVAP-related, while transmission symptoms in Civics from this era often involve the CVT and related fluid, sensors, or control issues.
• Prioritize a systematic diagnostic path: EVAP system health first, then CVT/transmission health if EVAP repairs don’t resolve the reported symptoms.
• For budget planning, prepare for inexpensive EVAP-related fixes (gas cap up to a few hundred dollars) and recognize that CVT-related transmission work can be more costly (potentially thousands if a major repair or replacement is needed). Always obtain a detailed estimate before any major work.

If you’d like, I can tailor a diagnostic checklist or provide city-specific cost estimates based on your location and preferred repair shops.