Emissions Archives - Page 5 of 47 - UnderhoodService
Finding Failing O2 Sensors

Oxygen sensors are some of the most often replaced sensors. Inputs from the O2 sensors are used by the engine management system to adjust the fuel mixture. This is critical for maintaining low emissions and good fuel economy. If an O2 sensor gets “lazy” because of old age or contamination, the computer may not be able to adjust the fuel mixture quickly enough as the engine’s operating conditions change. O2 sensors that are failing tend to read lean, which causes the fuel system to run overly rich to compensate. The result is increased emissions and fuel consumption.

Oxygen sensor
Ford EGR-ESM Diagnosis

The EGR system module (ESM) is one of Ford’s latest EGR system for gasoline engines. It is an EGR valve, EVR, MAP and DPFE sensor rolled into one package. Though the DPFE sensor on an ESM is referred to as “DPFE” by the scan tool and also wiring diagrams, it is not a traditional DPFE sensor as used on the older EGR system. It is actually two separate MAP sensors.

egr esm 2
EGR System Trouble Code Fixes

Testing EGR System Trouble Codes P047A and P047B on Volkswagens with the Tier2 BIN5 TDI 2.0L CBEA Diesel EGR System.

PCV Valve Facts

The first vehicle to get a positive crankcase ventilation (PCV) valve was the M5 Stuart tank in WWII, which was made by Cadillac. The valve replaced draft tubes that might suck water into the engine while crossing rivers.

PCV valve
Understanding EVAP: From The Tank To The Intake

Modern EVAP systems are selective when they vent vapors into the engine. The PCM will select the right engine temperature and throttle position to purge the system. They are also very selective when system checks are performed. A computer is constantly monitoring the results of the commands sent to the valves with the help of sensors mounted in the tank and EVAP canister.

EVAP Leak Diagnostics

On its own, any leak detection device can be a powerful tool to detect leaks. In the wrong hands, using these can lead to comebacks and parts being replaced needlessly. But, when one of these devices is paired with service information, training and most importantly a scan tool, it can lead to a more profitable and productive diagnostic process.

EVAP system
Catalytic Converter Replacement Commandments

Catalytic converter replacement can be one of the most arduous repairs a shop takes on. It is not that the repair itself is overly complicated; it is the paperwork, laws and warranty issues that can be the real headache.

Induction Cleaning Service For Direct-Injection Vehicles

You may have seen it before: misfire codes, stumbling and suspicious fuel trim numbers. On a scan tool, the engine may show a loss in volumetric efficiency. The driver may complain about a loss of power, poor fuel economy, hard starts and a rough idle. But this is not a 12-year-old engine; it is only

Getting the Complete Picture on Converter Efficiency

Engine ­management ­systems ­compensate for changes in engine speed, loads and temperatures by adjusting the amount of fuel injected, spark ­advance/retard and even when the intake and ­exhaust valves open. These adjustments can only do so much. Tailpipe emissions are cut further by exhaust gas recirculation (EGR) and ­secondary air injection systems. The last line

Diagnosing Catalytic Converter Failure Symptoms

Although construction can vary according to engine application, the common three-way catalytic converter contains a reduction and oxidation stage. To create maximum surface area, each stage is generally a ­ceramic or stainless steel honeycomb substrate covered with a rough silica and alumina wash coat. Both stages of the converter are coated with precious metal catalysts

catalytic converter diagnostics
PaceSetter Performance Products Offers Direct-Fit Manifold Catalytic Converter For 2002-’08 Mini Cooper S, 1.6L Engine

PaceSetter Performance Products, designers and manufacturers of quality-made, affordably-priced exhaust systems and components, now offers a direct-fit manifold catalytic converters for the 2002-’08 Mini Cooper S with the 1.6L engine. PaceSetter Direct-Fit Catalytic Converters utilize mandrel-bent stainless steel tubing for maximum efficiency and CNC-machined thick steel flanges for a factory-like fit and good seal. This

PaceSetter Performance Products Offers Direct-Fit Undercar Catalytic Converters For 2005-’07 Subaru Outback, 3.0L Engine

PaceSetter Performance Products, designers and manufacturers of quality-made, affordably-priced exhaust systems and components, now offers direct-fit catalytic converters for the 2005-’07 Subaru Outback with the 5.7L engine. PaceSetter Direct-Fit Catalytic Converters utilize mandrel-bent stainless steel tubing for maximum efficiency and CNC-machined thick steel flanges for a factory-like fit and good seal. This ‘under-car’ catalytic converter