CONVERTER BASICS

STANDARD LOAD EURO 2 Meets EPA Emissions Standards

MAGNAFLOW EPA OBDI compliant universal catalytic converters are designed to meet or exceed all requirements for aftermarket replacement converters. MagnaFlow produces these converters in a variety of configurations including traditional clam shell & more compact spun body designs. Covering both gas and diesel, MagnaFlow’s Standard Load converters provide comprehensive pre-OBDII coverage.

HEAVY METAL EURO 3

Upgraded to exceed EPA emissions standards HEAVY METAL catalytic converters are EPA OBDII compliant converters. They are engineered to satisfy both fitment and performance requirements of early OBDII applications. As vehicles transitioned from OBDI to OBDII converters became an integral component of the emissions control system. Oxygen sensors not only monitored engine air/fuel ratios but catalyst efficiencies as well. MAGNAFLOW’S HEAVY METAL converters provide the necessary precious metal loading to satisfy early OBDII catalyst efficiency monitoring as well as tail pipe emissions.

OEM GRADE EURO 4

Engineered to meet California emissions levels OEM Grade catalytic converters are MagnaFlow’s premium converter. Utilizing our experience in successfully developing and manufacturing CARB approved catalytic converters, we have engineered a product line to address the needs of late model 49 state OBDII vehicles. As California 50 state emissions certified vehicle sales outside of California are growing, so has the need to provide a product line that can adequately service them. MAGNAFLOW’s OEM Grade catalytic converters ensure compatibility with stringent late model OBDII vehicle emissions’ requirements. Not only is the substrate volume increased, but these converters are formulated with higher precious metal content and EFN specific wash coats to satisfy each application’s oxygen storage needs preventing false-fail emissions codes.

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CONVERTER BASICS Until recently tail pipe testing for emissions has been the standard for most states with an Emissions Testing program. Over the last few years however many states have converted to OBDII testing for all light duty vehicles 1996 and newer.

THE TESTING CONSISTS OF SEVERAL STEPS TO CONFIRM THAT A VEHICLE IS IN COMPLIANCE • Verify NO Codes in System • KOEO - Verify MIL Bulb Check • KOER – Verify MIL NOT Illuminated • Verify Readiness Indicators (Monitors are complete) • Diagnostic Connector Verification and Scan Tool Communication

A REVIEW OF OBDII TESTING FROM AROUND THE COUNTRY EXPOSES A LIST OF COMMON FAILURES:

• P0420 - bank 1 catalyst efficiency below threshold • • • • • • • • •

P0300 – Random Misfire P0401 – EGR Insufficient Flow P0171 – Fuel Trim, Bank 1, System Too Lean P0174 – Fuel Trim, Bank 2, System Too Lean P0135 – O2 Sensor Heater Circuit, Bank 1 Sensor 1, Malfunction P0325 – Knock Sensor 1, Circuit Malfunction P0440 – Evaporative Emission Control System Malfunction P0442 - Evaporative Emission Control System, Small Leak Detected P0455 - Evaporative Emission Control System Large Leak Detected

Although these are not in any specific order of occurrence, the five codes following the P0420 can directly affect the efficiency of the converter or the computer’s ability to monitor it correctly.

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CONVERTER BASICS CATALYTIC CONVERTER DESCRIPTION & OPERATION The catalytic converter is a passive aftertreatment device designed to reduce engine-out emission levels to meet an acceptable standard. Together with the Oxygen Sensors and other Engine Management components, this Emissions System works to reduce harmful emissions at the tail pipe. The catalytic converter contains two or more ceramic substrates, coated

with a combination of Platinum, Palladium and Rhodium and a Ceria based wash coat, packed into a stainless steel housing. When placed in the right environment of heat (400°C) and proper air/fuel mixture the catalyst forces a chemical reaction reducing toxic gasses to less harmful ones.

OBDII CONVERTER EFFICIENCY There were many changes that took place with the implementation of OBDII but the change having the greatest affect on diagnostics was the Readiness Monitors. During operation, the on-board computer (PCM), continually tests itself and all emission com-

ponents reporting to it. This monitoring process assures each component or system is operating within a pre-programmed set of parameters. The Catalyst Monitor utilizes pre and post converter oxygen sensors to continually check the oxygen storage capacity

of the converter. During normal operation, the pre-cat O2 or Sensor 1 should display a rapidly changing voltage signal ranging from approximately 0V to 1V. The post-cat O2 will be flat line displaying little or no variation in its signal.

P0420 DIAGNOSTICS & TESTING A P0420 (Catalyst System Bank 1 Efficiency Below Threshold) or a P0430 (Bank 2), are indicators that the converter may not be functioning properly, but are not the end of the diagnosis. There are a number of steps that must be taken to assure that the root cause of the failure is found and repaired.

• Test drive the vehicle and note any driveability issues that may indicate fuel or spark delivery problems such as hesitation, stumbling, spark knock, or misfire. • Check the tail pipe upon start-up. Look for any signs of smoke that would indicate an engine failure such as oil burning (blue), internal coolant leak (white) or rich running condition (black). • Listen carefully for any signs of vacuum or exhaust leaks. • Complete visual inspection of ignition, fuel and intake components. • Scan Tool test. Avoid clearing codes until ‘Freeze Frame’ information can be retrieved. This is a snap shot of what was going on with the vehicle when the code was set such as temperature, vehicle speed, load, throttle position etc. Using this information you can duplicate the conditions that set the code in the first place.

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CONVERTER BASICS TEMPERATURE & SHELL DISCOLORATION Catalytic converter shell coloration is a good indicator of Converter efficiency and light-off. Converter efficiency depends on factors including exhaust gas composition and temperatures. Converter internal reactions (light-off) begin to occur at exhaust gas temperatures between 400° and 800° C. High operating temperatures should be avoided to prevent degradation of the converter. Always note any conditions that may prevent a converter from reaching light-off temperature.

EXHAUST COMPONENT INSPECTION

UPON REMOVAL OF CONVERTER

• Check manifold and exhaust pipes for leaks

• Melted substrate

• Check for any physical damage to the converter housing • O2 sensor wiring to ensure good contact at the connectors and no damage or shorted wires

• Check for missing, cracked or loose substrate • Severe discoloration indicating excessive temperature • Excessive build-up of carbon, soot or oil on the inside of converter and/or connecting pipes

P0420 DIAGNOSTICS & TESTING Along with current codes, also look for any history or pending codes. Any fuel trim related issues will have a direct affect on the converters ability to function properly. These include but are not limited to: MISFIRE: P0300-P0314 O2 SENSOR CIRCUIT: P0130-P0147, P0150P0167 HO2S HEATER CONTROL CIRCUIT: P0030-P0038, P0040, P0043, P0044, P0050P0064 AIR FLOW CIRCUIT: P0100-P0140 FUEL SYSTEM: P0170-P0175 INJECTOR CIRCUIT: P0200, P0261-P0296

• Check the OBDII Readiness Indicators (Monitors) to ensure all have been run to

• Check Short and Long Term Fuel Trim data (STFT /LTFT). STFT is directly related to the switch rate of the O2 Sensor 1 and is an indicator of current fuel control. LTFT is an indicator of the PCM’s fuel trim history and is a good way to determine if the vehicle has a history of running lean or rich. Either one of which could cause premature failure of the converter. LTFT is given in percentage. A lean running engine displays a positive % because the PCM will be adding fuel to compensate while a negative % tells us the computer is trying to over come a rich running engine.

completion. One or more that read incomplete may indicate that the codes were cleared recently and you may not have a complete picture of the status of the engine and all its components. • Check all scan data looking for anything that would indicate an area of concern. For a more product info and up-to-date dyno charts/sound clips go to: www.magnaflow.com

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CONVERTER BASICS TECHNICAL SERVICE BULLETIN Technical Service Bulletins or TSB’s are published by the manufacturer to address particular issues, repairs or updates to a vehicle’s systems or components. Advances in technology have created scenarios whereby a software update to the vehicle’s computer may be all that is needed to repair a driveability issue. Intermittent MIL (Check Engine light) illumination, premature or false codes are also instances

that might only call for a software update. Reprogramming or reflashing are terms commonly used to describe these operations. TSB’s are very specific and will clearly spell out what vehicles, systems and components the bulletins are addressing and what actions are to be taken including any updated components and/or reprogramming necessary for a proper repair.

CAUSES OF CATALYTIC CONVERTER FAILURE Here are some common component failures that can lead to converter damage: • Intake leak • Exhaust leak • Fuel Injector leakage • Defective front O2 sensor • Defective Mass Air Flow meter (MAF) • Defective Manifold Absolute Pressure sensor (MAP) • Defective Engine Coolant Temperature sensor (ECT) Following are the more common contaminants that will affect O2 and converter performance: • Oil – bad rings or valve seals • Sulfur – found in some low quality gasoline • Silicone – found in most gasket sealants unless marked “O2 sensor safe” • Coolant – damaged head gaskets or intake plenums

CONVERTER REPLACEMENT TIPS • Choose the right converter through application look-up • Replacement converter should be in same position as OE • Install all oxygen sensors as close to OE position as possible • Maintain all heat shields for proper converter light-off • Always check for leaks after repairs

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For a more product info and up-to-date dyno charts/sound clips go to: www.magnaflow.com