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.
2003 Mitsubishi Lancer EvolutionFACTORY OEM SERVICE PROCEDURE
EGR System Check
- Disconnect the vacuum hose from the EGR valve, and then connect a hand vacuum pump via the tee-fitting.
- Start the engine. Check the vacuum condition when the throttle valve is opened suddenly (revving) during cold and hot engine conditions. Expected results:
- Cold engine: No vacuum.
- Warm engine: Vacuum momentarily rises over 3.9 in. Hg (13 kPa).
- Stop the engine. Remove the tee-fitting and the hand vacuum pump.
- Connect the hand vacuum pump directly to the EGR valve.
- Start the engine and run at idle until warm.
- The engine idling speed should be rough when the specified amount of vacuum is applied to the EGR valve:
- Lancer, Lancer Evolution VIII & Outlander - 7.9 in. Hg (27 kPa) or more.
- All others - 8.7 in. Hg (29 kPa) or more.
- If engine idles rough, EGR passage is open and the system is okay. If engine idle is not rough, the EGR passage and the valve must be checked for restrictions. Perform the EGR valve check, see EGR VALVE CHECK . Repeat the EGR system check.
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.