Converter Basics - Supercat Converters

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.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
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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.
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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