Thanks to advanced electronic
controls, today’s engines are more powerful, cleaner and more efficient than
ever before, but everything wears out, burns out or breaks. Delaying
check engine light repairs can lead to reduced fuel
economy and even collateral damage. For example, the check engine light might be
on due to a spark plug or thermostat issue, but ignoring it could result in
catalytic converter failure.
Even if your vehicle seems to be operating well for the moment, it’s important
to resolve small issues when your check engine light comes on to avert bigger
problems. There’s no need to panic, but have your vehicle scanned, diagnosed and
repaired as soon as possible.
Contaminated MAF
The mass air flow (MAF) sensor samples and measures air going into the intake system, but blockage or contamination can skew sensor readings, leading to fuel trim problems. Cleaning it might help, but sometimes the vehicle requires a replacement sensor for a sure fix.
It is a good idea to clean the MAF sensor every time you change or clean the air filter. A clean MAF sensor can restore 4-10 horsepower to the wheels, which is a significant number for just cleaning a sensor. Do not use MAF sensor cleaners on Karman-Vortex style air flow sensors, which are found in Toyota Supra turbos, Mitsubishi, and most Lexus engines. Most important do not use contact cleaner to clean your sensor. Miatafun has MAF cleaner specifically for cleaning the MAF sensor without damaging the fine heater wire. We do charge a $5.00 fee for the cleaner and will do the removal and install after cleaning for you if you would like. This is a good Tech day project.
The common DTCs related to the MAF sensor are P0171 and P0172.
Faulty Oxygen Sensor
Oxygen sensors monitor fuel trim and catalytic converter functioning, depending on location. Uncorrected fuel trim, due to a faulty oxygen sensor or heating circuit, results in higher emissions, lower fuel economy and possible damage to the catalytic converter.
The common DTCs are P0030, P0131 and P0165.
Faulty Ignition
Ignition coils, spark plug wires and spark plugs are designed to deliver a precisely timed spark to burn fuel in the cylinder, but damage or weakness can lead to incomplete combustion or misfire. A faulty ignition should be remedied immediately.
The common DTCs are P030x and P035x
EVAP Problems
To keep unburned fuel vapors from contaminating the atmosphere, a system of tubes, valves and a charcoal canister store them until they can be burned in the engine. This is called the evaporative emission control, or EVAP, system. Faulty valves are common, but refueling while the engine is running or forgetting to install the gas cap are more common, all of which can trigger the check engine light.
The common DTCs related to the EVAP system are P0440, P0446 and P0455
Failed Catalytic Converter
The catalytic converter reduces emissions from harmful compounds found in car exhaust by converting them into less harmful compounds before they leave the exhaust system. However, overheating, underheating or contamination can reduce its effectiveness and lead to your check engine light illuminating.
The common DTC for this issue is P0420
Hope this helps with some of those pesky check
engine light problems so we can get in our cars and enjoy driving.
