Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1990 Plymouth Voyager LE, 2.5 J, Automatic, A604FACTORY OEM SERVICE PROCEDURE
EGR Valve/BACKPRESSURE Transducer Assembly
- Check vacuum hoses for correct routing. Warm engine to normal operating temperature. Connect a vacuum pump to EGR valve. With engine idling, slowly apply 2-3 in. Hg. Engine RPM should drop when vacuum is applied.
- Disconnect vacuum pump from EGR valve. Connect vacuum gauge to EGR vacuum supply hose. Start engine and raise engine speed to 2000 RPM. Vacuum gauge should read about 5 in. Hg. If test results are as specified, system is okay.
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:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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