Tech Tip: No Start in Cold Weather Due to No Weep Hole
This condition can be caused by condensation freezing in the muffler assembly. Follow this procedure for correction.

Do Oxygen Sensors Generate Electricity?
They are made of zirconium oxide, a chemical compound used to form the sensor’s thermal-driven electrochemical fuel cell.

EGR, Secondary Air Injection And Emissions Management
EGR systems put a small amount of inert gas into the combustion chamber to control the temperatures.

How To Diagnose Slow or Sluggish Oxygen Sensors
When oxygen sensors are tested, manufacturers will introduce small amounts of oil to measure sensitivity.

E-15 Ethanol Damage to Fuel Pumps
One of the problems with ethanol is how it reacts to water in the air and in the tank.

Oxygen Sensor Questions Answered
If an O2 sensor is not reading properly or is borderline, it should be replaced regardless of its age or mileage.

Managing (DPF) Diesel Particulate Filter Regeneration Cycles
The DPF is designed to store the soot and ash, to later burn them off during a regeneration cycle.

Ultimate Underhood – Gasoline Particulate Filters
Just like a DPF, a gasoline particulate filter (GPF) traps and stores soot particles in the exhaust stream.

Why O2 Sensors Fail To Calculate Exhaust Levels Over Time
As miles accumulate, O2 sensors effectively “catch a cold,” meaning they can’t breathe like they should.

Clearing The Air About Diesel Exhaust Fluid (DEF)
Reducing emissions to acceptable levels is achieved through a four-stage process.

Emissions 101: A Basic Understanding Of How Catalytic Converters Operate
To begin, an internal combustion engine creates heat energy by igniting a mixture of gasoline and atmospheric oxygen with a high-voltage spark.

10 Commandments Of Catalytic Converter Replacement
It is not that the repair itself is overly complicated; it is the paperwork, laws and warranty issues that can be the real headache.
