What are symptoms of faulty catalytic converter 1989 ranger STX?

Answer 1

If the converter is plugged, contaminated, damaged or rusted out, it must be replaced. Likewise, if the OBD II system is showing low catalyst efficiency, the converter must be replaced. Driveability symptoms such as a drop in fuel economy, lack of high speed power, rough idle or stalling are classic symptoms of excessive backpressure due to a plugged converter. Checking exhaust backpressure and/or intake vacuum will tell you if there's a blockage. The important point to remember is that converters don't just plug up or die for no good reason. There is usually an underlying cause which must also be diagnosed and corrected before the problem can be eliminated. Diagnosing a plugged or fouled catalytic converter is only half the fix. Replacing a bad catalytic converter will only temporarily restore things to normal because unless the underlying problem that caused the original converter to fail is identified and fixed, the replacement converter will likely suffer the same fate. Always replace the O2 sensor if the converter needs replacing. That may not be all that needs to be done. A defective spark plug or wires, or a burnt exhaust valve will also destroy the converter.