Tech Tip: Multiple Cylinder Misfire or Rough Idle on Chrysler Models This bulletin involves rotating all engine exhaust valves, replacing the valve spring retainer locks with a new design to increase valve rotation at lower rpm, inspecting/replacing the MAP sensor (as necessary), and decarbonizing the combustion More

Tech Tip: Wave Dynamics for Headers and Pipes Depending upon the market to which an import shop might be catering, the term "performance exhaust" can have two different meanings. The first market actively seeks out the throaty rumble and chrome-plated look as part of the street-driving scene. The second market installs an exhaust system that produces the most horsepower for a performance application. Sometimes the two markets are identical and... More

Catalytic Converter Diagnosis The catalytic converter is probably the most important emission control device on a vehicle because it cleans up the pollutants in the exhaust. Thanks to fuel injection, oxygen sensors in the exhaust manifolds, and a feedback fuel control system, emissions are kept to a minimum. Even so, some pollution is still produced and must be eliminated by the converter. So the converter must be in good condition... More

Diagnostic Solutions: Exhausting the Possibilities...Performance Upgrades Depending upon the market to which an import shop might be catering, the term “performance exhaust” can have two different meanings. The first market actively seeks out the throaty rumble and chrome-plated look as part of the street-driving scene. The second market installs an exhaust system that produces the most horsepower for a performance application. Sometimes the two markets are identical and... More

Performance Exhausts for Late-Model Vehicles What’s hot in exhaust performance products? Bolt-on free-flowing exhaust systems for diesel trucks, big bore mufflers for sport compact cars, and low restriction street performance mufflers for cars like Mustangs, Pontiac G8s, Dodge Chargers and Chevy Corvettes. The diesel market has been really hot lately. Turbo diesel engines are a popular option in full-size Dodge, Ford and GM... More

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 as greatly as the life span of the vehicle itself. One catalytic... More

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 it, he can’t call it. The engine controller is like the referee in that it continuously monitors... More

Diagnostic Solutions: Catalytic Converters The design and function of catalytic converters has changed dramatically since their introduction in 1975. The first “two-way” catalytic converters were oxidizing-only designs that combined hydrocarbon (HC) and carbon monoxide (CO) with oxygen to form water vapor (H2O) and carbon dioxide (CO2). Oxidizing converters were originally manufactured in pellet bed or monolithic “honeycomb” styles. Currently... More

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 vehicle inside and out. However, not all of the 2004 F150s that you see will be the new body style. The 2004 F150... More

Tech Feature: Performance Modifications...Getting a ‘Handle’ on Your Customers’ Tuning Needs The sport compact car market is hotter than ever. The market has moved beyond the simple bolt-ons such as wheels, tires, brake rotors and spoilers. It’s not unusual today to see sport compact engines producing upward of 400 horsepower on the street. With so much power under the hood, the challenge is getting the horsepower to the tires and maintaining reasonable traction and handling. More