How to Remove a Smog Pump

by Chris Stevenson

All vehicles emit a certain amount of harmful emissions into the atmosphere which pollute the environment. These emissions have been taken more seriously in recent years with the advent of devices and components that lessen or remove the toxic substances. Smog pumps, or air injection pumps, have been designed to help with this task, and now have become part of a vehicle's emission control system. Smog pumps recirculate harmful exhaust gases back into the intake system, where they burn more completely. With wear and age, the smog pump must be removed.


Place the vehicle in park or neutral with the emergency brake set. Raise the hood. Disconnect the negative battery cable with a socket and wrench. Hook up a shop light that has a cord long enough to place under the vehicle or over the engine compartment.


Use the floor jack to lift the vehicle and place two jack stands under the front frame near each wheel. Use the floor jack to lift the rear of the vehicle and place two jacks under the frame near each wheel. Refer to your owner's repair manual for the location of your smog pump. Some are accessible from the engine compartment (on top), while others must be removed from underneath the car.


Position the shop light for optimum visibility. Use a socket and wrench to loosen the three bolts on the smog pump pulley. Do not remove the bolts completely. If the pulley turns during loosening, shove the heel of your hand on the belt to tighten its tension, then loosen the bolts. Let the pulley remain intact for now.


Use a socket and wrench to unload the pressure on the tensioner pulley, if you have a serpentine belt. Place the socket on the center tensioner nut and turn it clockwise. Hold it there and slip the belt off the smog pump pulley. For the single belt configuration, loosen the main smog pump mount bolt only a few turns. Loosen the upper adjusting bolt on the smog pump, then shove the pump down to slacken the belt tension. Slip the single belt off the smog pump pulley.


Use a slot screwdriver to loosen the clamp on the large (rubber) discharge hose, connected to the nozzle outlet on the smog pump. Twist and pull the hose from the nozzle, and be careful not to tear or crack it during removal. Use a socket and wrench to loosen the upper smog pump bolt and remove it. Keep track of spacer sleeves or washers that might fall down. Finish loosening and removing the smog pump pulley bolts with a socket and wrench. Take the pulley out.


Use the socket and wrench to remove the main (lower) smog pump mounting bolt. Pull the pump out from its bracket mount and out of the engine compartment. Use a small socket wrench to remove the elbow discharge nozzle (on certain models) from the smog pump, if you find insufficient clearance to remove the pump between the other components. If you still find insufficient clearance to remove the pump, use a socket and wrench to loosen and remove the bolts that holds the combination valve to the smog pump housing. Pull the combination valve out first, then remove the smog pump.

Items you will need

About the Author

Chris Stevenson has been writing since 1988. His automotive vocation has spanned more than 35 years and he authored the auto repair manual "Auto Repair Shams and Scams" in 1990. Stevenson holds a P.D.S Toyota certificate, ASE brake certification, Clean Air Act certification and a California smog license.

Photo Credits

  • photo_camera red truck engine image by Christopher Nolan from