Check engine light is on. The gas cap is okay and the vent sensor by crankcase seems okay too. What could it be?
Dignotic test showed air flow, checked gas cap, some sensor of or by crankcase. Any thing you could help with?
My car has 102376 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
The issue could be the evaporative emission vent purge valve on the vapor charcoal canister. I recommend using a sniffer that is used for butane and check for a fuel leak around the vent purge valve and see if there is a gross leak. If so, then I recommend replacing the vent purge valve on the vapor charcoal canister. If you need further assistance with your check engine light being on, then seek out a professional, such as one from Your Mechanic, to help you.
How to Identify and Fix Common car Problems ?
Our sources include academic articles, blog posts, and personal essays from experienced mechanics :
The most common reasons a Mercury Grand Marquis has a check engine light are an emissions system component, a sensor, or a catalytic converter. Search our network of RepairPal Certified shops near you to speak with a technician about your issue.
The Evaporative Emission Control System (EVAP) is used to prevent gasoline vapors from escaping into the atmosphere from the fuel tank and fuel system at all times.
Trouble Code: P0456 Evaporative Emissions System – Small Leak Detected. The EVAP system is a closed system that captures fuel tank vapors and prevents them from escaping into the atmosphere.
A loose gas cap is one of the most common reasons for the check engine light to go on. Check that your gas cap is screwed on securely and that it`s in good condition. If you have a tank of bad gas in the car, your check engine light may come on.
These problems can range from faults within the electrical system, the engine, fluid levels or to problems within the car`s emissions system. The problem can even be as simple as forgetting to tighten your gas cap – in fact, this is the most common reason why check engine lights appear in the first place.
Sometimes, the check engine light comes on to let you know that there`s a problem with the car`s internal diagnostic mechanism. That means the system could be “finding” a problem that doesn`t exist, or it could be that loose wire systems are creating a false positive in the system.
The most common causes for EVAP leaks include bad seals and O-rings, a failing purge valve, a damaged hose or vent, or a defective leak detection pump. As you might have guessed, there`s no real way to prevent one of those components from failing unless you`d like to regularly replace components of your fuel system.
An EVAP trouble code could be caused by something as simple as a loose or worn gas cap, a leak in a hose, problems with a purge valve or even a rusty fuel filler pipe. When your Check Engine light comes on, bring your vehicle into Auto Select and let us check it out.
The P0720 code is a standard OBD-II trouble code that detects an issue with the output speed sensor circuit. The powertrain control module (PCM) relies on a signal from the output speed sensor, so that it can determine the correct shift strategy and send that information to the transmission.
P0420 is a diagnostic trouble code (DTC) for “Catalyst System Efficiency Below Threshold (Bank 1)“.
Connecting to an OBD-II Port
You plug an OBD-II scanner tool into it and, in most cases, out pops a code that tells you what the problem is. The scanner also allows you to clear the vehicle`s internal code, which is what triggered the check-engine light. Do that, and the warning light will turn off.
Can you drive a car with the engine light on? It`s okay to drive for a few miles, but be sure to schedule an inspection of the engine as soon as possible. If the check engine light comes on while you`re driving, don`t panic! Pay attention and see if the car is driving any differently than normal.
Bottom line: Yes, if you see a pattern in which the engine light comes on during periods that your tank is low, then turns off right after you fill it (and tighten the gas cap!), one of the above issues is probably going on.
Bad Sensors
One common culprit for this problem is the crankshaft position sensor, which measures the position and speed of the crankshaft. The computer uses the information from this sensor to know when to fire the spark plugs. If the sensor isn`t working, the spark plugs won`t fire, keeping the engine from starting.
Yes. While the damage may seem small initially, the longer you drive with a bad oxygen sensor, the worse the damage will become. Eventually, you may experience rough idling, poor acceleration, engine misfires, an illuminated check engine light, and failed emission tests.
Check your gas cap first. Many vehicles have a loose gas cap indicator that will be triggered before your check engine light comes on. If your gas cap is loose or the seal is not tight, the vapor leakage can cause your fuel system to trigger the check engine light.
The reasons for a check engine light turning on can range from something minor like a loose gas cap to something more serious like a faulty catalytic converter. It could even be a sign of internal engine failure. Ignoring the problem can turn a potentially quick fix into a costly and time-consuming repair.
Clearing the check engine light can cause your car to fail smog. If you`re trying to pass a smog test, clearing the check engine light isn`t a fix. Yes, a car will automatically fail a smog check if the check engine light is on. However, clearing codes won`t make it pass.
The reasons for a check engine light turning on can range from something minor like a loose gas cap to something more serious like a faulty catalytic converter. It could even be a sign of internal engine failure. Ignoring the problem can turn a potentially quick fix into a costly and time-consuming repair.
Clearing the check engine light can cause your car to fail smog. If you`re trying to pass a smog test, clearing the check engine light isn`t a fix. Yes, a car will automatically fail a smog check if the check engine light is on. However, clearing codes won`t make it pass.
Clearing the check engine light can cause your car to fail smog. If you`re trying to pass a smog test, clearing the check engine light isn`t a fix. Yes, a car will automatically fail a smog check if the check engine light is on. However, clearing codes won`t make it pass.
The reasons for a check engine light turning on can range from something minor like a loose gas cap to something more serious like a faulty catalytic converter. It could even be a sign of internal engine failure. Ignoring the problem can turn a potentially quick fix into a costly and time-consuming repair.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Check engine light is on. The gas cap is okay and the vent sensor by crankcase seems okay too. What could it be?
ANSWER : The issue could be the evaporative emission vent purge valve on the vapor charcoal canister. I recommend using a sniffer that is used for butane and check for a fuel leak around the vent purge valve and see if there is a gross leak. If so, then I recommend replacing the vent purge valve on the vapor charcoal canister. If you need further assistance with your check engine light being on, then seek out a professional, such as one from Your Mechanic, to help you.
Gas cap notification and check engine light came on after getting gas. Car started to sputter and stall out.
ANSWER : Hi there. When the fuel cap is not securely fastened to the tank, it can create vacuum issues inside the tank; which triggers the error code to be stored in the ECU. The error will then trigger the check engine light until that code is reset by a professional digital scanner. If you’re still having sputtering or stalling issues, you should contact a professional mechanic to complete an engine sputtering inspection. This will allow them to diagnose what’s causing this problem and reset any error codes to hopefully correct the issue your Chrysler 300 is experiencing.
check engine light O2 sensor already replaced same codes still popping up after replacing old O2 sensor
ANSWER : Hi there. What you received from the parts store was a code retrieval, not a diagnostic. The codes are set when a fault is detected against normal operating parameter. The computer does not know what caused the fault, only that the fault meets the criteria for this code to set. There could be a problem in the wire harness, converter, or the ECM. The code and data are needed to properly assess the direction that a diagnosis needs. I strongly suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a check engine light inspection.
Car started to slow down and then the check engine light, battery, and engine oil light came on. What could cause this?
ANSWER : Hi there. It is possible that the battery cable came loose or the wires to the oil pressure sensor has came loose or failed. Check the battery cables and make sure that the terminals are tight and clean. Check the wires to the oil pressure sensor and make sure that they are connected and not broken. If everything looks good, then the oil pressure sensor may have failed. Plus, check the computer for codes and see what is stored. This will lead you to the part that could have failed. I recommend replacing the oil pressure sensor then checking to see if the lights will go out. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from Your Mechanic, that can assist you with the warning lights that came on.
Traction light/reduced engine power and check engine light coming on
ANSWER : Hello. From what you describe, it would appear that your vehicle may be experiencing some sort of intermittent wiring or sensor issue. If the problem occurred again after driving over a bump, then it may be possible that a damaged or loose wire is shorting or having contact issues. A common issue that can cause stalling is a faulty crank position sensor or wiring. I would carefully examine the engine for any loose or damaged wires. If the Check Engine Light comes back on, I would recommend having the trouble codes scanned before resetting the computer.
Idle problems when stopped. Car stops running. 4WD and Check engine lights on and solid. Gas cap tightened to verify
ANSWER : What you are describing sounds like a dirty or faulty mass air flow sensor. The mass air flow sensor monitors air intake as it is mixed with fuel prior to being injected into the motor. This sensor relays vital information to the ECM which uses this to make adjustments to fuel supply to the motor. A dirty or faulty sensor can cause an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. I would suggest having a professional from Your Mechanic come to your home to diagnose and inspect your vehicle.
While driving on freeway truck goes into a limp mode, and the check engine light, abs light, parking break light, service brake
ANSWER : It is possible that you could be having an issue with your powertrain control module. This is somewhat of a common problem on many GM vehicles. I would recommend having your vehicle inspected by the dealership to determine if the powertrain control module is functioning properly. If not, a reflash of the powertrain control module may resolve the issue but often times it must be replaced.
O2 sensors changed, but check engine light still showing code after clearing it I checked fuse. Wires are good and used Denso OE.
ANSWER : Depending on what the code was for will determine if the oxygen sensor was to be replaced. If the conditions were for a rich or lean mixture and it said oxygen sensor, then the spark plugs and wires could need replaced if its a rich reading or the fuel injectors could be clogged or not working if its a lean mixture. If the code said that the oxygen sensor was bad, then check the harness and see if there is a break in the wiring or a short to ground in the wiring from the oxygen sensor to the main harness. If you need further assistance with your check engine light being on, then seek out a professional, such as one from Your Mechanic, to help you.
