(Set) can be used with the NOVITEC or the original exhaust system (-9 Lbs) 100 Cell metal sport cats with reduced exhaust back pressure. Optional High-temperature heat protection coating for the set. We recommend the TECTRONIC unit to remove the CEL that will be triggered due to replacing the cats. The TECTRONIC can only be ordered at the time of purchase of the cat replacement pipes or sport cats. It cannot be order at any other time.