1983 Mazda B2000 BaseFACTORY OEM SERVICE PROCEDURE

Air By-Pass Valve

  1. Disconnect air by-pass valve-to-exhaust manifold hose from air by-pass valve. Start engine and run at idle. Place finger over air by-pass valve outlet and make sure air is escaping.
  2. Increase engine speed and quickly release accelerator. Air should stop flowing for a few seconds. If air does not flow out or air flow lasts for more than 3 seconds, replace air by-pass valve.
Fig 1: Testing Air By-Pass Valve Illustration applies to Calif. vehicles only.
G40245
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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