Emissions Archives - Page 22 of 24 - UnderhoodService
Hot Tips From Hot Rod Builders

Sometimes the best opportunities are cleverly hidden in plain view. As one example, when Chris Lafferty of Lafferty Engine Creations was asked why he opted to expand beyond race engines into the hot rod and muscle car arenas, he snorted, “Just look outside.” His North Carolina facility sits squarely in the middle of both NASCAR

Mercedes: Addressing MIL Issues

‘Systems Operation’ Knowledge and Proper Equipment Saves Diagnostic Time and Speeds Repair Process It may not be a Mother-in-Law light, but the effect can be about the same. Just when you don’t want to see it, there it is! The Malfunction Indicator Light (MIL) has been around for more than 25 years, but since OBD

EGR Issues: Dealing with P0401 Codes

ht=”245″ alt=”” align=”right” /> As emission controls got tighter, and with the advent of OBD II, things started to change. We not only saw additional driveability complaints, but we also had the check engine light (CEL) telling the customer there was an emissions failure that had to be dealt with for the good of the

Mischievous Cats

By definition, a catalytic converter should last the lifetime of the vehicle. It can last this long because a catalyst is something that, just by being present, causes a reaction to other materials without itself being a participant in the reaction. However, real life has proven that the life span of a catalytic converter varies

Oxygen Sensors: Pulse Measurement

Watching an oxygen sensor output on an oscilloscope is like watching a sporting event on television. You get to see the action, but can do nothing about it as it happens. Sometimes you miss the action and want an instant replay. It was a bad call. You saw the interference. If the referee didn’t see

Foreign Affairs: VW P Codes — … Putting Out The MIL

After 10-plus years of dealing with OBD II, it should be apparent that we are on a learning curve that probably has no end. Almost daily we have a Volkswagen model come into the shop with a check engine light on, or a “state OBD II failure” form. Although we have the latest scanner software

Maintenance Essentials…, OBD II & Chassis Checks

All cars need maintenance. The fact is mechanical devices wear and fail in normal use, and deteriorate over time, so being able to diagnose a future failure has become a part of the automotive repair and service industry. Customers always ask how long it will be before a component will fail, and are usually not

Diagnostic Dilemmas: Symptom Diagnosis…The Journey Begins

When I first began my automotive career way back in 1957, the symptoms of an ailing engine were very apparent. A carburetor with a worn accelerator pump, for example, would characteristically stumble on acceleration and a closed-up set of distributor contact points would cause the engine to become very sluggish. Low fuel pressure caused by

Foreign Affairs: Getting Nissan Engines Back to Peak Performance

/Articles/06_01_2007/60754gif_00000014067.gif” width=”156″ height=”146″ alt=”” border=”0″ align=”right” /> In this article, we’ll take a look at some of the common problems that affect engine performance. With on-board diagnostics (OBD), many of these problems will cause a check engine lamp (CEL) and store a code. With most of us becoming comfortable and proficient while working with OBD

Emissions Analyzers: What is Really Going On Inside that Engine?

An emissions analyzer is one of the most useful pieces of diagnostic equipment you can own. Scan tools are great for reading fault codes and sensor data, but a scan tool by itself can’t tell you what is actually going on inside the engine’s combustion chambers. A scan tool can read misfires and tell you

When Should You Replace an Oxygen Sensor?

Is there a mileage or time requirement for oxygen sensor replacement? Simple answer: No. Oxygen sensors were first used for fuel trim and emissions in the late 1970s and into the mid 1990s. A single sensor was installed into the exhaust stream to modify fuel delivery and maintain catalytic converter efficiency. Beginning January 1, 1996,

Service Guide: F-Series New Model 2004

A bold new look and some subtle changes probably best describe the 2004-and-up Ford F150. To the technician, it is the subtle changes that he or she needs to be aware of. Starting with the 2004 model year, Ford launched a new body style for the F150. The new body style truck is a new