Catalytic converter Ford F150

Note: Because of a Federally mandated extended warranty which covers emissions-related components such as the catalytic converter, check with a dealer service department before replacing the converter at your own expense.

General description

1. The catalytic converter is an emission control device added to the exhaust system to reduce pollutants from the exhaust gas stream. The three-way catalyst lowers the levels of oxides of nitrogen (NOx) as well as hydrocarbons (HC) and carbon monoxide (CO).


2. The test equipment for a catalytic converter is expensive and highly sophisticated. If you suspect that the converter on your vehicle is malfunctioning, take it to a dealer or authorized emissions inspection facility for diagnosis and repair.

3. Whenever the vehicle is raised for servicing of underbody components, check the converter for leaks, corrosion, dents and other damage. Check the welds/flange bolts that attach the front and rear ends of the converter to the exhaust system. If damage is discovered, the converter should be replaced.

4. Although catalytic converters don’t break too often, they can become plugged. The easiest way to check for a restricted converter is to use a vacuum gauge to diagnose the effect of a blocked exhaust on intake vacuum.

  1. Connect a vacuum gauge to an intake manifold vacuum source.
  2. Warm the engine to operating temperature, place the transmission in Park (automatic) or Neutral (manual) and apply the parking brake.
  3. Note and record the vacuum reading at idle.
  4. Quickly open the throttle to near full throttle and release it shut. Note and record the vacuum reading.
  5. Perform the test three more times, recording the reading after each test.
  6. If the reading after the fourth test is more than one in-Hg lower than the reading recorded at idle, the exhaust system may be restricted (the catalytic converter could be plugged or an exhaust pipe or muffler could be restricted).


5. Be sure to spray the nuts on the exhaust flange studs before removing them from the catalytic converter(s).

6. Remove the nuts and straps and separate the catalytic converter from the exhaust system.

7. Installation is the reverse of removal

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