What does the p0421 code on the Check Engine light mean?
What the P0421 code means. The powertrain control module uses data received from the upstream and downstream oxygen sensors and compares the two readings given. If the two readings are identical, or very close to each other in value, the Check Engine Light will be illuminated and a P0421 code will be stored.
What does the p0171 code mean on a check engine light?
If it needs to correct the air-fuel mixture more than that, the P0171 code will be stored. If the fuel mixture is slightly lean, you will often get no other symptoms from the P0171 code other than the check engine light on your dashboard.
What causes a p0171 code on a PCV valve?
Here are the most common fixes to the P0171 code. Most common from the top. A common diagnostic mistake is to start replacing parts without making a proper diagnosis. In most cases, the P0171 code is caused by something easy as a vacuum leak or a bad PCV valve.
Can a faulty MAF sensor cause a p0171 code?
If you start replacing MAF sensors, O2 sensors, etc., you will probably spend a lot of money without results. A faulty O2 sensor is not a very common cause of the P0171 code, even if many people start to replace it directly when they see this code. Diagnosing the P0171 code is easy if you have the right tools to do it.
What to do if check engine light code p0171 is triggered?
If check engine light code P0171 is triggered again, check the rest of the vacuum lines for leaks and continue to the rest of the diagnostic process. Remove the mass airflow sensor and clean the sensor using mass air flow cleaner or contact cleaner.
What are the symptoms of a p0421 code?
Symptoms of a P0421 code a driver may experience would include: 1 The Check Engine Light will be illuminated 2 The engine may not start 3 The engine may lack power or hesitate upon acceleration 4 Strange noises may be heard while driving
What does Bank 1 of p0171 mean?
Code P0171 Definition Bank 1 has too much air or not enough fuel. What Does P0171 Mean? Combustion engines run most efficiently when they maintain an air-fuel mixture ratio of 14.7 parts air to 1 part fuel.
What does p0421 mean in Powertrain Control Module?
The P0421 code means that the powertrain control module is noticing that the catalyst system is not performing as it should during warm up conditions.