Browse

Property For Sale Property For Rent

Used Cars Others

Antiques Collectibles Apparel Baby Kids Items Books， Movies And Music Electronics Free Stuff Garden Outdoor Health Beauty Home Goods Home Improvement Supplies Musical Instruments Office Supplies Others Pet Supplies Sporting Goods Ticket Toys Games Transportation

Business Crafts Design And Web Events Home Improvement Legal Lessons Personal Pets Photography Repair And Technical Support Wellness Writing， Translation， And Transcription Others

Activities & Groups Artists & Musicians Classes & Lessons Events Friendship & Networking Lost & Found Rideshare Sports Teams Volunteers Travel & Travel Partners Skills & Language Swap Other

What Causes Engine Emission Faults?

2 Answers

StPatrick

08/29/25 2:48am

Engine emission faults can be caused by sensor issues, maintenance problems, fuel quality issues, poor combustion of the air-fuel mixture, etc. The details are as follows: Sensor Issues: When the water temperature sensor, crankshaft position sensor, air flow sensor, intake air temperature sensor, or oxygen sensor is damaged, has poor contact, or experiences signal interruption, the car's ECU cannot accurately obtain engine data. Maintenance Problems: Failure to perform regular maintenance and poor driving habits can increase the operational burden on the engine. Fuel Quality Issues: The fuel added to the car must meet specified octane ratings. Failure to use the required fuel can cause engine wear. Poor Combustion of the Air-Fuel Mixture: This can lead to engine carbon buildup or knocking issues, which the engine's oxygen sensor will detect.

Was this review help?

17

1

Share

OAlexandra

09/10/25 7:33am

Last time when the engine emission warning light came on, I panicked while driving and immediately checked for possible causes. Common issues include a faulty oxygen sensor, which monitors oxygen levels in the exhaust pipe and provides feedback to the ECU for adjusting the fuel mixture ratio; or a clogged catalytic converter that fails to effectively filter pollutants; carbon buildup in the EGR valve can also disrupt exhaust gas recirculation. Poor fuel quality shouldn’t be overlooked either—low-grade fuel with excessive impurities may clog fuel injectors, causing an imbalanced air-fuel mixture. Once, I even discovered an air leak in the intake system, allowing unmetered air to enter and leading to calculation errors. For daily maintenance, it’s best to schedule regular upkeep, such as cleaning the throttle body and sensors every six months to prevent minor issues from escalating. Diagnosis is straightforward—just use an OBD tool to scan for trouble codes, saving time, money, and ensuring peace of mind.

Was this review help?

1

5

Share

Expand All

More Forum Discussions

What Causes a BMW to Sound the Alarm for No Reason?

There are several reasons why a BMW may sound the alarm for no apparent reason: 1. The trigger sensitivity is too high: This is one of the common reasons for car alarms to sound without cause. Such alarms may also operate intermittently, activating even with minor vibrations or low-level noise. Sometimes, excessive vibration or noise can also trigger the alarm. If the alarm is too sensitive, there is usually a sensitivity adjustment knob on the anti-theft vibration sensor that can be fine-tuned. 2. Doors not properly closed: This includes not just the car doors but also the engine hood or trunk. If any of these components are not securely closed, the car alarm may activate. If not addressed, the alarm will continue to sound until the car battery dies or the door is properly closed. 3. Controller malfunction: The alarm may also sound if the alarm controller is faulty, experiencing a short circuit or failure.

What engine does the 2019 Land Rover Discovery have?

The engine of the 2019 Land Rover Discovery is independently developed by Jaguar Land Rover and produced in Changshu. The 2.0T version of the 2019 Land Rover Discovery has an engine model PT204, with a maximum power of 221kW, a maximum torque of 400 Nm, and a maximum horsepower of 300. The 3.0T version has an engine model 306PS, with a maximum power of 250kW, a maximum torque of 450 Nm, and a maximum horsepower of 340. For the daily maintenance of the 2019 Land Rover Discovery engine, the following methods can be used: Use lubricating oil of appropriate quality grade. For gasoline engines, SD--SF grade gasoline engine oil should be selected based on the additional devices of the intake and exhaust systems and usage conditions; for diesel engines, CB--CD grade diesel engine oil should be selected according to mechanical load, with the selection standard not lower than the manufacturer's requirements; Regularly change the oil and filter. The quality of any grade of lubricating oil will change during use. After a certain mileage, performance deteriorates, causing various problems for the engine. To avoid faults, change the oil regularly according to usage conditions and keep the oil volume moderate; When oil passes through the fine holes of the filter, solid particles and viscous substances in the oil accumulate in the filter. If the filter is blocked and oil cannot pass through the filter element, the filter element may burst or the safety valve may open, allowing oil to pass through the bypass valve and bringing dirt back to the lubrication area, accelerating engine wear and increasing internal pollution; Regularly clean the crankcase. During engine operation, high-pressure unburned gas, acid, moisture, sulfur, and nitrogen oxides from the combustion chamber enter the crankcase through the gap between the piston rings and cylinder walls, mixing with metal powder from part wear to form sludge. A small amount remains suspended in the oil, while a large amount precipitates, blocking the filter and oil holes, making engine lubrication difficult and causing wear; Regularly use a radiator cleaner to clean the radiator. Removing rust and scale not only ensures the normal operation of the engine but also extends the overall lifespan of the radiator and engine.

Should the Nissan Patrol Y62 use 92 or 95 octane gasoline?

According to the official vehicle manual recommendation, the Nissan Patrol Y62 should use 95 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual, you can also find it marked on the fuel tank cap of the Patrol Y62. Generally, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should use 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should use 95 octane gasoline. However, with the application of new technologies, the compression ratio alone cannot determine the gasoline grade. High compression ratio engines can also be tuned to use lower octane gasoline because, besides the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline octane number, the higher the octane value and the better the anti-knock performance. 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. If the Patrol Y62 occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower octane gasoline, using higher octane gasoline will not cause damage, but the increase in octane value will change the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in poorer performance. For vehicles recommended to use higher octane gasoline, using lower octane gasoline can cause engine knocking. Because the octane value is too low, the gasoline's ignition point decreases, causing premature ignition during the compression stroke. If the fuel ignites before the spark plug fires during the compression stroke, resistance will occur during the upward stroke. This resistance makes the engine run very unstable. If the knocking is mild, it may only increase noise without significant engine damage. However, if noticeable knocking occurs, it indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.

What model is the BMW 7201LM?

BMW 7201LM belongs to the BMW 5 Series. Here are detailed introductions about the BMW 5 Series: 1. Overview: The domestic 5 Series is a high-end sedan. The current fifth generation was born in 2004. BMW's 5 Series is one of the most outstanding series in automotive history, with its peak era starting from the third generation E34 (1988-1996). The current 5 Series is the third generation product of E34. 2. Others: The exterior dimensions of the BMW 5 Series are 5047*1860*1491 (millimeters), with a wheelbase of 2888 millimeters. The new 5 Series is 66 millimeters longer than the previous generation. The top version 545i is equipped with a V8 engine from the 7 Series, with a maximum power of 245 kW/333 horsepower (6100 rpm), a maximum torque of 450 Newton meters (3600 rpm), and a top speed of 250 kilometers per hour.

What is the speed limit in urban areas without speed limit signs?

In urban areas without speed limit signs, the speed generally should not exceed 30 km/h or 50 km/h. Below is a detailed explanation of speed limits in urban areas without speed signs: 1. Roads without center lines: According to Article 45 of the 'Regulations for the Implementation of the Road Traffic Safety Law', the speed for motor vehicles on roads without speed limit signs or markings is clearly defined. On roads without center lines, the speed limit is 30 km/h for urban roads and 40 km/h for highways. 2. Roads with only one motor vehicle lane in the same direction: When there is only one lane in the same direction, the speed limit is 50 km/h for urban roads and 70 km/h for highways.

What to Do When the Car Door Won't Close Due to the Latch Being Stuck?

If the car door won't close because the latch is stuck, you can remove the door lock screws and pull the latch outward slightly to resolve the issue. Here are some additional details: 1. Adjusting the door latch: First, remove the screws on the door latch. Then, you can see the latch and slightly adjust its position inward or outward to ensure the door locks securely without needing excessive force to close. 2. The design requirements for car doors include: ensuring ease of entry and exit for passengers, with the maximum opening angle controlled between approximately 65 to 70 degrees. During the opening process, the door should not interfere with other parts. When closed, the door must lock securely to prevent opening while driving and should have good sealing performance.

Trending Ranking

Will a Car Fire Extinguisher Explode if Left in the Vehicle?

How to reset the vehicle trip?

What is the real fuel consumption of the Skoda Rapid?

How to Use a Paint Thickness Gauge?

What is the fuel consumption of the Trumpchi GS4?

At what voltage can a car battery no longer start the engine?

How to Find the Reference Points for Pulling Over in Driving Test Part 3?

Precautions for Signing a Used Car Purchase Contract

What is the reason for the EPC light turning on and off while driving?

What does Porsche PSM mean?

More Forum Discussions

Why are there fewer people buying the BMW X4?

What is the difference between multi-link independent suspension and torsion beam rear suspension?

Why doesn't the car beep when locking?

What Causes Electric Vehicle Motors to Overheat?

Help

Cookie

Cookie Settings

© 2025 Servanan International Pte. Ltd.