A COMPLETE DIAGNOSTIC MANUAL
FOR TROUBLESHOOTING THE
OBDII CATALYTIC CONVERTER

Following is a complete Diagnostic Manual in helping you diagnose and troubleshoot problems with a vehicles emission system and the possible replacement of emission parts including the catalytic converter.

TIGHTENING PROCEDURE FOR
ALL MANIFOLD CONVERTERS

WHAT IT MEANS WHEN YOUR GET A CODE READ OF PO420 OR PO430

It is important to remember that if the "Check Engine Light" illuminates and you read a code of PO420, 421, 430 or 431 this does not necessarily mean the Catalytic Converter is bad!  All the code says is either Converter operating below efficency or Converter operating under threshold.  Nowhere does the code say that the converter is bad. 

The vehicle may very well need a Catalytic Converter but to determine this you should perform proper engine diagnostics.  The  reading of a simple code is NOT performing diagnostics.  The following material should give you a better understanding of what proper diagnostics consist of and how they should be performed. If after reading the material below you still have questions please give us a call, 817-551-7700, and we will do all we can to help you solve the problem.

TECHNICAL INFORMATION BULLETIN

GENERAL MOTORS 3.5L & 3.9L ENGINES

The Vehicle Emission Control Label is located under the hood of your car
and will help you identify the type of emissions platform
that your vehicle came equipped with from the factory. 
These labels may be one of these locations:

Vehicle Recall:
2010 Chevrolet Equinox
2010 GMC Terrain

What Does the Term California Emissions Mean?