| Table of Contents | |
| Possible Causes of P0455 & Their Repair Costs | Code P0455 indicates a small leak is detected in the evaporative emission control (EVAP) system. |
| How to Diagnose The Cause of Your P0455 Code | Pinpoint the likely cause of the P0455 code. Common culprits include a loose gas cap, malfunctioning charcoal canister, faulty purge or vent valve, or cracked EVAP hose. |
| Can I drive with a P0455 code? | Yes. It’s okay to drive with a P0455 code for a few weeks. Don’t ignore repairs to avoid continued or worsening problems. |
| DIY | How To Fix P0455 Causes |
DIYable P0455 triggers include:
|
| P0455 Code FAQs |
Frequently asked questions:
|
Gasoline is an essential element for most vehicles with an internal combustion engine. However, this fuel evaporates, releasing harmful hydrocarbons into the atmosphere. To combat this problem and comply with federal emissions regulations, automakers developed the evaporative emission control or “EVAP” system. Over time, problems can arise with technology, including diagnostic trouble code (DTC) P0455: Evaporative Emission Control System—Large Leak Detected.
A check engine light occurs for this issue when the engine control module (ECM) or powertrain control module (PCM) detects a large leak following an onboard diagnostic test (which the ECM conducts periodically). Other EVAP leak-related codes include P0442, P0456, and P0457. Although not directly tied to an EVAP leak, other related codes include P0440, P0441, and P0443.
The EVAP system keeps gasoline vapors in a pressurized environment until the fumes are sent to the engine for combustion. A leak, which can occur at many points, depressurizes the system, which causes the ECM to generate an error. In the case of code P0455, the leak is of sufficient volume to be classified as large.
A leak causing a P0455 code is a low-severity problem despite the size. This isn’t an issue to ignore, but one that should get attention in the next few weeks. That said, treat the trouble more urgently if there’s a strong smell of gasoline; these fumes are toxic and combustible. In addition, code P0455 leads to increased emissions, reduced fuel economy, and challenges with emissions testing.
Diving into the P0455 code, we’ll unpack its frequent triggers, telltale signs, and go-to fixes. We’ll also spotlight which makes and models are known offenders when it comes to this particular problem.
Possible Causes of P0455 & Their Repair Costs
While code P0455 is a low-priority problem, its reduced seriousness doesn’t help when it comes to finding the leak. EVAP leaks are notorious for being difficult to detect, especially for novice DIYers without professional equipment.
Check out the FIXD article on the most common causes of check engine lights.
Here’s a quick look at the typical parts involved in P0455-related repairs.
| Part To Repair | Part / DIY Price | Mechanic Total Cost |
| Replacement gas cap | $20–$60 | N/A |
| EVAP Purge Volume Control Valve | $44–$55 | $120–$131 |
| Charcoal Canister Vent Control Valve | $50–$65 | $126–$141 |
| Replacement EVAP Line | $30–$70 | $106–$146 |
| Fuel Tank Pressure Sensor | $127–$129 | $264–$304 |
| Charcoal Canister | $362–$391 | $453–$507 |
These numbers reflect average prices. Some cars may require more repair time or higher-priced components.
Let’s examine how these parts signal a P0455 code.
| Parts that can cause P0455 | How it could cause P0455 |
| Gas Cap | A faulty gas cap creates an escape path for fuel vapors. |
| EVAP Purge Volume Control Valve | A malfunctioning purge valve prevents the correct vapor flow from the charcoal canister to the engine. |
| Charcoal Canister Vent Control Valve | A stuck-open vent control valve permits air into the EVAP system. |
| EVAP Line | A damaged EVAP line allows fuel vapors to exit the EVAP system. |
| Fuel Tank Pressure Sensor | A faulty fuel tank pressure sensor can incorrectly report pressure levels, leading the ECM/PCM to mistakenly interpret these false readings as a large leak in the EVAP system (and generate a DTC). |
| Charcoal Canister | A damaged or defective charcoal canister can’t effectively absorb and store fuel vapors, compromising the EVAP system’s functionality. |
Makes Commonly Affected By P0455
FIXD sensor data reveals that code P0455 problems aren’t exclusive to one manufacturer or model. It’s an issue that impacts many makes and nameplates. However, some brands have a bad history with this DTC.
Leading the pack, and not in a good way, is Nissan. Its venerable Altima gets tagged as the most likely vehicle to experience a P0455 code. The Altima’s truck-based stablemates, the Titan and Frontier, follow but at more moderate occurrence levels.
Chevrolet takes second place in the dubious list, with the Impala being the leading vehicle from the Bow Tie brand for code P0455 events. The stalwart Silverado 1500 has an equally high occurrence rating, while the Equinox settles into mid-range territory for this DTC.
Toyota occupies third place on this dubious list, which includes high occurrence levels for the hyper-popular Corolla and Camry. Meanwhile, the 4Runner finishes out the top Toyotas with long histories of P0455 codes.
The Blue Oval slides behind Toyota, with Escape and Edge crossovers being Ford’s worst offenders for code P0455 incidents. The storied Mustang also occupies a spot. However, when averaging all assessed model years, no Ford had a high occurrence level for this DTC, unlike the previously mentioned automakers.
Jeep completes the top five. The Grand Cherokee and Wrangler have medium incident levels for P0455, while the Liberty has a low rating.
| Top 5 Makes Affected by P0455 | Most Affected Model(s) | |
Nissan | Altima | |
| Titan | ||
| Frontier | ||
Chevrolet | Impala | |
| Silverado 1500 | ||
| Equinox | ||
Toyota | Corolla | |
| Camry | ||
| 4Runner | ||
Ford | Escape | |
| Edge | ||
| Mustang | ||
Jeep | Grand Cherokee | |
| Wrangler | ||
| Liberty | ||
How to Diagnose The Cause of Your P0455 Code
Diagnosing a check engine light starts with using an OBD-II scanner to identify what’s causing the issue. The FIXD plug-in sensor will show the code and likely causes on your phone via the accompanying FIXD app. You can also try a basic code reader with a cable to plug into the car’s OBD-II port. In truth, there are only a few things a novice DIYer can do to identify what triggered a P0455 code. You’ll want a flashlight, gloves, safety goggles, and a rag to get started. A more involved effort will require essential hand tools.
Safety Essentials
Before exploring the source of a P0455 code, you’ll want to observe the following:
- Park on a level surface in a safe area
- Ensure the car is off and the parking brake is engaged
- Allow the engine to cool
Symptoms of P0455 Causes
For a novice DIYer, dealing with a P0455 can be broken into two categories: simple and not-so-simple. There are basic tasks (see below) that almost anyone can tackle. However, you’ll need professional assistance if these actions don’t solve the problem.
Click on each Possible Cause of a P0455 code to know the symptoms to look out for and what to inspect.
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
Firmly twist the gas cap onto the fuel filler neck until you hear multiple clicks, confirming it’s fully sealed and correctly positioned.
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
Check the gas cap for any damage, particularly on the rubber seal at its base.
For vehicles with capless fuel systems (common in Ford, Honda, and Chrysler models), verify the spring-loaded flap and surrounding parts are intact and functional.
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
Take off the gas cap and examine the top edge of the filler neck where it joins the inlet for any cracks or holes
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
Thoroughly inspect all EVAP system hoses for damage or leaks, focusing on their connection points to the charcoal canister and fuel tank.
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
These symptoms are best investigated by a professional technician.
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
These symptoms are best investigated by a professional technician.
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
These symptoms are best investigated by a professional technician.
Symptoms:
- Illuminated check engine light
- Decreased fuel economy
- Fuel aroma
- Increased vehicle emissions
What to Inspect:
Inspect the charcoal canister for damage or leaks. Consult a professional technician for a more thorough diagnosis.
Check to see if any P0455-related technical service bulletins (TSBs) have been issued for your car. This information can often help pinpoint trouble spots with the EVAP system.
Can I drive with Code P0455?
Quick answer: Yes, driving for up to a few weeks with a P0455 code is okay. However, don’t ignore this problem for an extended period.
While any check engine light is sure to increase stress, at least one caused by a P0455 code isn’t the worst thing that can happen. Continued driving is acceptable. Just be sure to have the problem fixed within a few weeks. You’ll also want to speed up repairs if a mandatory emissions test is on the horizon (the car isn’t likely to pass otherwise). In addition, the sooner you resolve this problem, the sooner your vehicle will return to normal fuel economy and emissions standards.
Here’s a more detailed look at driveability with a P0455 code.
| Causes | Can I Drive? | Risks / Safety / Performance |
|---|---|---|
|
Faulty Gas Cap |
Yes, driving for a few is acceptable, but don’t delay repairs for too long. |
Reduced fuel economy, increased vehicle emissions, and the likelihood of failing emissions tests. |
|
Damaged EVAP line |
Yes, driving for a bit is acceptable, but don’t delay repairs for too long. |
Reduced fuel economy, increased vehicle emissions, and the likelihood of failing emissions tests. |
|
Faulty EVAP Purge Volume Control Valve |
Yes, driving for a while is acceptable, but don’t delay repairs for too long |
Reduced fuel economy, increased vehicle emissions, and the likelihood of failing emissions tests. |
|
Defective Charcoal Canister Vent Control Valve |
Yes, driving for a few is ok, but don’t delay repairs for too long. |
Reduced fuel economy, increased vehicle emissions, and the likelihood of failing emissions tests. |
|
Faulty Fuel Tank Pressure Sensor |
Yes, driving for a bit is ok, but don’t delay repairs for too long. |
Reduced fuel economy, increased vehicle emissions, and the likelihood of failing emissions tests. |
|
Malfunctioning Charcoal Canister |
Yes, driving for a few is acceptable, but don’t delay repairs for too long. |
Reduced fuel economy, increased vehicle emissions, and the likelihood of failing emissions tests. |
DIY | How To Fix P0455 Causes
DIY fixes for a P0455 focus on simple tasks, like swapping out a gas cap. You can handle this repair if you’ve filled up a car at a gas station. We’ve also included a task that requires moderately more skill and experience.
While DIY repairs can save money and be rewarding, it’s crucial to recognize your limits. Attempting fixes beyond your abilities can worsen the problem, make repairs more costly, and become an injury risk. Know when to seek expert help.
Possible Cause: Damaged or Defective Gas Cap
What is it?
A properly functioning gas cap maintains fuel system pressure. If the cap is loose, misaligned, or damaged, it can cause a pressure drop and vapor leak, potentially triggering a P0455 code. An improperly closed or defective gas cap can lead to the same problem.
How hard is it to fix?
Difficulty Level: Easy
Fixing a gas cap issue is simple: ensure it’s tightened correctly or replace it with a compatible, quality cap. After the repair, drive your vehicle for a few cycles or use a diagnostic tool (like the FIXD app) to clear the check engine light and P0455 code. Avoid cheap replacements that may not seal properly.
Cost of Repairs
There’s no expense if the problem is traced to a misaligned gas cap. Otherwise, a replacement costs $20 to $60.
Possible Cause: Faulty EVAP line
What is it?
A damaged EVAP line can cause system leaks, triggering the P0455 code. In this case, replacing the faulty hose usually fixes the issue.
How hard is it to fix?
Difficulty Level: Moderate
Replacing a faulty EVAP hose varies in difficulty based on its location. Engine bay repairs are often manageable for those with moderate skills. However, hoses near the axle, suspension, or gas tank may require professional help due to limited access. After the repair, drive the vehicle for several cycles or use an OBD-II scanner to clear the check engine light.
Cost of Repairs
A replacement EVAP line usually costs $30 to $70.
Other DIY Considerations for Code P0455
EVAP repairs get more challenging when tracking down a leak, which usually requires a specialized smoke machine. For the average car owner, you’re better off spending the money on a mechanic’s diagnostic services rather than buying a device you’re unlikely to need very often.
In addition, swapping out a bad purge or vent valve, fuel tank pressure sensor, or charcoal canister isn’t overly complex. The trick lies in accessing parts that can be buried deep within a car. A seasoned DIYer might be able to handle the work, but these are often tasks best handled by an experienced technician.
P0455 Code FAQs
What makes and models does code P0455 affect the most?
Here’s a breakdown of the vehicles most affected by code P0455, according to FIXD sensor data collected in 2023.
| Make | Model | Occurrence Frequency |
| Nissan | Altima | High |
| Chevrolet | Impala | High |
| Chevrolet | Silverado 1500 | High |
| Toyota | Camry | High |
| Toyota | Corolla | High |
| GMC | Sierra | High |
| Audi | A4 | Moderate |
| Chevrolet | Avalanche | Moderate |
| Chevrolet | Cobalt | Moderate |
| Chevrolet | Colorado | Moderate |
| Chevrolet | Equinox | Moderate |
| Chevrolet | Malibu | Moderate |
| Chevrolet | Suburban | Moderate |
| Chevrolet | Tahoe | Moderate |
| Dodge | Ram 1500 | Moderate |
| Ford | Edge | Moderate |
| Ford | Escape | Moderate |
| Ford | Mustang | Moderate |
| Ford | Ranger | Moderate |
| GMC | Yukon | Moderate |
| Jeep | Grand Cherokee | Moderate |
| Jeep | Wrangler | Moderate |
| Nissan | Frontier | Moderate |
| Nissan | Titan | Moderate |
| Toyota | 4Runner | Moderate |
| Toyota | Prius | Moderate |
| Toyota | RAV4 | Moderate |
| Toyota | Tacoma | Moderate |
| Toyota | Tundra | Moderate |
Why are some makes and models more vulnerable to a P0455 code than others?
Certain vehicles may experience P0455-related issues more frequently due to specific engineering choices or issues during the manufacturing process. Factors can include the complexity of the EVAP systems, the quality of materials used in components like hoses and seals, or the positioning of EVAP components that may expose them to more wear and tear. Also, certain automakers may use parts from suppliers with higher failure rates for EVAP system components.
How can I prevent P0455 from occurring?
To prevent P0455 codes, regularly inspect and maintain your vehicle’s EVAP system components. Ensure your gas cap is always appropriately tightened after refueling (a few clicks are usually all that’s required), and periodically check for visible damage to EVAP hoses and connections. Schedule routine maintenance checks to catch potential issues before they trigger the code.
What are common code P0455 symptoms?
The most common symptom of a P0455 code is the illumination of the check engine light. You may also notice a fuel odor, especially near the gas tank area. In some cases, you might experience reduced fuel efficiency due to escaping fuel vapors. A failed emissions test can also be traced to P0455-related problems.
References:
Repair-cost estimates, repairpal.com (various dates). Retrieved August 13, 2024, from repairpal.com.
Dave Goldberg is an automotive journalist and lifelong car fanatic. He writes for numerous enthusiast and business outlets and is an ongoing contributor to HotCars.com, one of the most popular car culture websites. When he’s not writing or driving, Dave is either under a hood or asleep. His credentials include a BA in Journalism from The George Washington University.
