Evap large leak code

My car is not passing emission test due to code P0455 on my car. I have changed my gas cap since that's what everybody is telling me to do first. After I changed the gas cap, I have deleted my code to check if it will come up again and it did. I have NO engine check light on my speedometer. Now I'm not sure if to change my purge valve solenoid or vent valve solenoid or my charcoal canister. Please I need an advise/solution.

My car has 161000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
If you have a large emission system leak the best way to find the leak is to do a smoke test and put smoke pressure in the fuel tank and it will show the smoke out of the system leak. The most common leak besides the fuel cap is the purge or vent valves. This test will pinpoint the valve that is leaking so it can be replaced. If you have no smoke machine then use a vacuum pump to check the purge valve to see if it holds vacuum? If it does not hold vacuum then replace valve.

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What does error code P0455 mean? The P0455 OBD-II code means the engine computer has detected an Evaporative Emissions Control System (EVAP) Malfunction or, to be precise, a `Gross Leak Detected`. Basically, this means there is a large leak in the EVAP system.
The P0455 diagnostic trouble code appears when there`s a leak in the Evaporative Emission Control (EVAP) system, and the system can`t maintain pressure. The EVAP system usually consists of five main components: the fuel tank, fuel cap, vent valve, purge valve, and the evaporative canister (or charcoal canister).
The purge valve opens when you start your vehicle, and an intake vacuum absorbs the harmful vapor into the engine for efficient combustion. However, a leak in the EVAP system would prevent vacuum creation. So, if the leak detection pump (LDP) detects a gross leak, the ECM generates code P0455.
What Does Nissan Code P0456 Mean? Nissan P0456 definition: Evaporative emission control system leak (small). Repair Urgency: Get this fixed within the next month to prevent drivability problems and excessive fuel consumption.
What causes the P0455 code? The leak can be caused from a variety of components. The most common is related to the fuel filler cap which could be missing, not correctly installed, not sealing properly or may be damaged to the top of the filler neck. The next most frequent problem is a leak in a hose.
During the leak test, the ECM closes the vent control valve to create a sealed EVAP system. If the EVAP system does not maintain the pressure, the ECM recognizes an evaporative emission control leak. In the case of P0455, it is a very large leak. This is usually indicative of a loose, broken, or missing gas cap.
p0455 just indicates a system leak. Nothing about improper operation by any of the solenoids. I`d say look for a leak or if you know somebody who vapes to blow some smoke into the tank to see if it`s leaking anywhere.
If you see a P0442 evaporative emission system leak detected code, you may be able to resolve the problem without much effort. The easiest solution may be to remove and reaffix the gas cap. Once you do, clear the code on the OBD-II diagnostic scanner and drive for a few days.
You may drive your vehicle while trouble code P0455 is present unless the gas vapor odors are very strong or you see obvious fuel (liquid) leaks. Extreme danger, seek repairs if either of these two scenarios exist. Note, a large fuel vapor leak may cause fuel economy issues.
An EVAP leak can cause a variety of issues, including a decrease in fuel efficiency, an increase in emissions, and a decrease in engine performance. If left unchecked, an EVAP leak can also cause damage to the catalytic converter, which can be expensive to repair.
P0455 GROSS LEAK DTC

On a GM, for example, a P0455 can be set by a vent solenoid, fuel tank pressure (FTP) sensor, the charcoal canister, vapor lines, hose connections, filler neck, the fuel tank itself – anything that can cause a leak of more than 20”.

The EVAP system is sealed and the most common components that can cause a leak are the gas cap, vent valve, and purge valve and the hoses and connectors, see the diagram below.
A P0451 code is an OBD-II fault code defined as “Evaporative Emission System Pressure Sensor/Switch.” This code is triggered when the vehicle`s Powertrain Control Module (PCM) detects an inaccurate or erratic voltage signal from the Evaporative Emission Control System Pressure Sensor.
While EVAP problems don`t generally lead to vehicle damage, the fact that they trigger the Check Engine light can mask other more serious problems if left unaddressed. After all, there are hundreds of conditions that can trigger a Check Engine light, but there is only one light.
A bad evaporative leak detection pump can cause your vehicle to fail a smog test. Many factors can cause a bad evaporative leak detection pump, but there is a single warning sign of a bad evaporative leak detection pump: Your Check Engine Light illuminates.
The P0420 code signals a low catalyst system efficiency. This code suggests that the oxygen levels are below the desired threshold (Bank 1), which most often results from problems with your car`s exhaust or fuel systems.
The code P0420 can be caused by the catalyst, O2 sensors before and after the catalyst. If both O2 sensors and catalyst was replaced then you may have an exhaust leak at the manifold or pipes.
Once you start your engine, a purge valve opens and an intake vacuum siphons the vapors into your engine to be burned. So, what does the code P0455 mean? A sensor has noted a large leak somewhere in the system so that a vacuum cannot be created.
Once you start your engine, a purge valve opens and an intake vacuum siphons the vapors into your engine to be burned. So, what does the code P0455 mean? A sensor has noted a large leak somewhere in the system so that a vacuum cannot be created.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Fuel EVAP line that runs under car is kinked how do I know if it is leaking? Also can I drive it like that if it’s not leaking?
ANSWER : Hi Ricardo. We answered your question earlier. However, if you didn’t receive the reply, here is what we stated earlier. In most cases, an EVAP leak will create an OBD-II trouble code. The best way to detect an EVAP leak is by having a professional mobile mechanic complete a check engine light inspection, they will be able to download the code and determine the source of the leak. That’s the best advice we can offer you. Thanks.

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White smoke coming from tailpipe with the code for evap large leak.
ANSWER : Hi there. The white smoke coming from the exhaust system indicates that there is water (coolant) in the exhaust system. This is caused by the coolant getting into the combustion chamber and burning off with the fuel. The coolant is coming into the combustion chamber through a burned head gasket. The evap system on the vehicle could be picking up a vapor from the exhaust or from the fuel vapor canister as the purge vent valve solenoid could not be working. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your engine and evaluate the smoke condition.

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EVAP Small Leak Code P0442 Lit MIL. Code cleared, has not reappeared. But, Diagnostic tool still shows Emission Related DTC’s
ANSWER : In order for all the monitors to clear you will have to do a lot of driving to see if it clears. The last two to clear take highway driving at a steady speed to clear and may take a couple times to clear or set a code if it cannot pass them after the testing has been done. The oil dipstick tube being loose will not cause the code you had. Keep driving the vehicle normal and it should pass all the monitors soon. I recommend having a qualified technician, such as one from YourMechanic, inspect the codes related to your Check Engine Light and diagnose the relevant systems more thoroughly in person.

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Jeep is throwing code p0441 and code 13. Checked front hoses. OK. Evap leak? Any help?
ANSWER : Hi – the P0441 code indicates that there is no flow of fumes detected from the gas tank/evap cannister to the engine. This could be caused by a faulty leak detection pump in the gas tank, failed purge valve, bad wiring to or a failed purge solenoid, blockage in the evap purge line, or even a failed engine management computer (not often). I would recommend having a Evaporative Emissions System Inspection completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.

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Fuel EVAP line that runs under car is kinked how do I know if it is leaking? Also can I drive it like that if it’s not leaking?
ANSWER : Hi there. In most cases, an EVAP leak will create an OBD-II trouble code, which is the best way to detect an EVAP leak. By having a professional mobile mechanic complete a check engine light inspection, they will be able to download the code and determine the source of the leak. In most cases, it’s an EVAP purge solenoid that is faulty.

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Check Engine Light codes. 2006 Mercedes Benz E55 AMG
ANSWER : Since you are getting many different codes from different areas of the engine, you may need to have the system hooked up to a factory scanner since most of these generic codes do not cross over in my repair software. I would also check with the local dealer to see if any service campaigns are open on the vehicle since there are over 30 possible campaigns that could pertain to this vehicle and some of the problems you are having with the secondary air system. This may be the cause of some of the codes and supercharger disabling. If you’d like to have this checked elsewhere, a qualified pro from YourMechanic can come to your car’s location to go through each Check Engine Light code firsthand and have them resolved.

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I have a Code P0601 on the PCM. I replaced the PCM, and now I have a code P0118, code P0123, and code P0193.
ANSWER : Hi there, the short answer to your question is no . A PCM with a P0601 (which is a memory module error in the PCM) cannot reliably retrieve codes for the codes you list (P0118 – coolant temp sensor, P0123 – throttle position sensor, P0193 – fuel rail pressure sensor.

Most likely, the P0601 prevents the PCM from getting any codes from the engine sensors. The memory module error may cause in data corruption for collected sensor values, lose of data over multiple sampling periods, or failure of the data collection to work at all. Replacing the PCM was a necessary expense.

If you need assistance with the "new" codes, I would recommend having a Check Engine Light inspection completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose the new error codes and get an accurate assessment of the repairs needed.

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P2402 code, Evap system warning and the leak
ANSWER : This is a fault for the evaporative emissions pump control circuit. This can mean the evaporative emissions pump is faulty. The evaporative emissions pump needs to be checked for function and then the evaporative emissions system needs to be checked for leaks caused by either a evaporative emissions valve or a faulty EVAP system connection. The system is commonly checked with a smoke machine to detect leaks. You may want to enlist the help of a mechanic, such as one from YourMechanic, who will have the equipment and training to diagnose your Check Engine Light further and repair any leaks that are present.

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