Why did my check engine light come on in my Toyota Corolla?
Toyota Corolla Check Engine Light Flashing Other common reasons for a Check Engine Light are dirty mass airflow sensor, faulty emissions control part, a malfunction with the fuel injection system, damaged oxygen sensor, faulty head gasket, or defective spark plugs to name a few.
What exhaust component can trigger a check engine light?
Your oxygen sensors are another emissions system part that will trigger your check engine light. Ironically, they aren’t really attached to the engine. They are screwed into your exhaust system in various places to monitor the air coming out of your engine.
What causes a check engine light to come on after a catalytic converter is replaced?
This trouble code appears when the unit can’t sufficiently reduce the carbon emissions from the exhaust. However, a catalytic converter does not normally wear out. There is usually some other reason for their failure. If you spend $900 or more to replace the catalytic converter, you may discover the check engine light coming on again later.
Do you have to have your catalytic converter repaired?
Even worse, you need to have an annual inspection soon, and your vehicle won’t pass unless you get your catalytic converter repaired. What the mechanic is not telling you is that it might just be a malfunctioning sensor, or the catalytic converter may be full of crud.
What kind of test should I do on my catalytic converter?
That’s necessary to detect catalyst efficiency accurately. A good mechanic might test by using a scope to diagnose the oxygen sensors or do a vacuum test or backpressure test, and just charge you a fee for the diagnostic service so that you can decide what you want to do as far as repairs are concerned. So what do you do?
Do you need to replace oxygen sensor before catalytic converter?
Some mechanics will tell you to try replacing the oxygen sensors first, to see if that solves the problem. There are two of them, one before and one after the catalytic converter. That’s necessary to detect catalyst efficiency accurately.