Codes po171, po174, po303, po741
I recently had my car tested and it showed the codes above. My service light is on but sturdy. I have lack of lpower and a rough idle. When I stop my car vibrates with surging on the acceleration. Prior to all of this I had spark plugs replaced and the light was still on. I was told that po352 was misfiring and had a front ignition coil replaced. I am still have problems. My car has been running great. I keep maintenance on my car but all this is new and I am a female, veteran as well as a senior citizen this is the only transportation I have and I want my car running smooth again. Please prov
Experienced mechanics share their insights in answering this question :
First, I would like to thank you for your service. I am also a veteran. Lets look at each code and their meaning first. Code P0741 is for a problem in the torque converter clutch seal in the transmission and requires the transmission to be removed and seals or components replaced as needed after inspection.
Code P0303 is a cylinder number 3 misfire and may be the spark plug, wire, or coil causing the misfire.
Codes P0171 and P0174 are for the engine on both banks 1 and 2 running too lean. This shows you may have a vacuum leak in the intake manifold or one of the hoses to the intake manifold. The code you had before P0352 was for an ignition coil problem. It looks like you have a few different problems that will need to be looked at by a qualified mechanic. I hope this will help you decide on a repair path for the codes you have. If you still need help, have a technician from YourMechanic come to your home or office to diagnose your Check Engine Light codes and make the correct repairs.
How to Identify and Fix Common car Problems ?
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When your powertrain/engine control module receives a reading that indicates there`s too much oxygen and the ratio is incorrect, it sends an error code P0171 or P0174. Depending on the problem, it may send both codes if the issue is causing a lean condition on both engine banks.
What is code P0174? The Diagnostic trouble code (DTC) P0174 indicates `System Too Lean (Bank 2). ` The P0174 engine code indicates that the air-fuel ratio in your vehicle is too lean. Before the gas in your car can combust and power your vehicle, it must first combine with oxygen.
What does the P0171 code mean? A Code P0171 or system too lean bank 1 means either too much oxygen or too little fuel in the exhaust. This is a `lean` condition or a `low fuel trim` code.
What the P0171 code means. The P0171 OBD-II code means that, on the first bank of the engine, the fuel system is running weak or a vacuum leak exists near this side of the engine. A lean condition occurs when the engine either receives too little fuel or too much air.
You probably know that the answer the questions is — no! A P0171 or P0174 lean code with an O2 sensor reading lean all the time mean — well, several things. The real problem may not be a bad O2 sensor, but possibly be an engine vacuum leak, low fuel pressure or dirty fuel injectors that are causing the engine run lean.
The most common cause of the P0171 code – and the P0170 and P0173-P0174 codes – is unmetered air entering the combustion system. Most of the time, this happens due to faulty or dirty mass airflow sensors or weak fuel pumps.
P0174 Causes
Below are some common causes of the error code P0174: A vacuum leak due to a damaged intake manifold gasket or a punctured vacuum hose. A malfunctioning mass airflow sensor (MAF sensor) A clogged fuel filter or weak fuel pump.
How Serious Is Code P0171? While it is common for a driver to only experience minor driveability problems when the P0171 trouble code is present, driving with this code can overheat the engine and cause internal engine damage.
What are the symptoms for a P0171 code? Generally, a lean code will cause the engine to run poorly, which the driver will notice as a high idle, a misfire, a lack of power, or even engine stalling, and this may happen before the check engine light has turned on.
If your sparks plugs have gone out, the OBD scanner should read the codes P0300 or P0171 which means lean running engine coupled with misfires.
The most common fault codes associated with a clogged fuel injector are P0171 and P0174, which indicates the engine controller is seeing a lean condition.
P0171 Causes
Some of the common causes for the DTC P0171 fault code include: A faulty fuel pressure regulator. A weak fuel pump. A clogged fuel filter.
No, either an air leak,low fuel pressure or a dirty fuel injectors can cause it. In my car it was caused by a bad fuel pressure regulator,I also got a P0174 which was for the right hand engine bank..
A lean fuel mixture occurs when there is too much air or not enough fuel in your engine. This can result in your car`s engine not operating optimally. Since there isn`t enough fuel being burnt, your car may stall, operate roughly or struggle to accelerate.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
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.
It threw a code 21 , throttle position sensor bad code. i replaced it and the code went away but i still have no spark.
ANSWER : Hello and thank you for contacting YourMechanic. The problems that you are encountering with your vehicle, could be caused by the harness to the Throttle Position Sensor (TPS) or the computer itself.
Check the harness to the TPS for any debris or any corrosion. Hook up a paperclip to the harness and turn on the key. Use a multimeter and check for voltage at the pins of the harness. Make sure that the ground on the sensor is grounded and has no resistance. If you find that the harness is having too much resistance, then I recommend having the main engine harness replaced. If you have replaced the harness and still have the same problems, then the computer will need to be flashed or replaced.
I recommend having a professional, like one from YourMechanic, come to your home to diagnose your car’s no start condition before replacing any parts.
Can i retrieve CEL code from car … forgot what code it hade in my car .. put headgasket sealer and i erase the code ..
ANSWER : Once a trouble code is erased, it cannot be retrieved. The engine controller does not have a "recycle bin" like they have on Windows. If the car still has a problem, the code will come back up after some driving. However, the controller will not turn on the CEL until it has seen the malfunction on two separate "trips." A "trip" is a driving cycle where the car is started cold, driven until it is fully warm and through a certain number of accelerations, and shut down. So you might not see the CEL for a couple of days. As for the "head gasket sealer," I wouldn’t hold out too much hope of that solving a problem. At the very best it might put off the symptoms for a short while. If you need help interpreting codes that come up, or solving a head gasket issue, contact Your Mechanic. They can send a technician to your home or office to read the codes on your car and help you decide what to do.
Codes po171, po174, po303, po741
ANSWER : First, I would like to thank you for your service. I am also a veteran. Lets look at each code and their meaning first. Code P0741 is for a problem in the torque converter clutch seal in the transmission and requires the transmission to be removed and seals or components replaced as needed after inspection.
Code P0303 is a cylinder number 3 misfire and may be the spark plug, wire, or coil causing the misfire.
Codes P0171 and P0174 are for the engine on both banks 1 and 2 running too lean. This shows you may have a vacuum leak in the intake manifold or one of the hoses to the intake manifold. The code you had before P0352 was for an ignition coil problem. It looks like you have a few different problems that will need to be looked at by a qualified mechanic. I hope this will help you decide on a repair path for the codes you have. If you still need help, have a technician from YourMechanic come to your home or office to diagnose your Check Engine Light codes and make the correct repairs.
I have a engine miss codes po174 po420 are on now I had code multiple cylinder miss fire. I changed spark plug wires and plugs l
ANSWER : Hi there. Your issue might be caused by a faulty O2 sensor. You might want to read this article about the P0174 OBD-II trouble code as it will show you possible causes, symptoms and solutions to resolve the problems.
I failed a smog check with the codes PO171 & PO174, saying the system is too lean on the bank 1 & 2. Can you tell me what the problem is?
ANSWER : Hi there. When the two codes P0171 and P0174 come up for a lean system on both banks of your engine, then either all of the fuel injectors are not working properly or your fuel pressure has dropped. Check the fuel pressure on the fuel rail and see what the pressure is at idle and when loaded. If the fuel pressure is less than 45 psi but greater than 15 psi, then the pressure regulator needs replaced. If the pressure is lower than 15 psi, but has more than 1 psi, then the fuel pump needs replaced. If you need further assistance with your emissions problem, then seek out a professional, such as one from Your Mechanic, to help you.
EGR code, Cylinder 4 misfire code 0304 detected.
ANSWER : Hi there. The Exhaust Gas Recirculation (EGR) valve may be not designed for the emissions requirements for U.S. standards. If the EGR is pulling from cylinder number 4 and after replacing the EGR and the computer detects a misfire, then the EGR is malfunctioning and not responding. When you close off the tube to the EGR and the EGR light comes on and the misfire light goes out, then the EGR is not responding to your emissions system. I recommend replacing the EGR with the OEM specified part for the engine and all of the issues should go away. If you need further assistance with your misfire and EGR, then seek out a professional, such as one from Your Mechanic, to help you.
Service engine warning, MAF code and O2 sensor code, along with check suspension light are turned on
ANSWER : Hello, it sounds like you have quite a few things going on. I am going to do my best to break them down for you.
First if the engine is very loud when idling and the belt has already been replaced, there may be an issue with the tensioner or idler pulley.
Next, the Navigator is known for needing service to the air suspension system as it gets up in miles, the most common causes of these are the air struts themselves have failed, or one of the air lines has a leak.
Lastly, if the O2 sensor and MAF are continually coming back after the sensors have been replaced, the most common cause would be either an exhaust leak or a vacuum leak.
Qualified technicians such as the ones at YourMechanic will be able to diagnose these issues and recommend the best path to repair, starting with a diagnosis of your warning lights.
