Perform thorough underhood inspection. Problems can frequently be resolved at this stage without further testing. Visually inspect the following:

- Vacuum hoses for proper routing, tight connections, splits, kinks, obvious tampering.

- Vacuum fittings for improperly capped or plugged ports. Be sure to check hidden areas around the throttle body and other components..

NOTE: Some manufacturers use an orifice-insert within a vacuum line as a delay device. Do not mistake such a device for tampering and remove it.

- Electronic Engine Control system wiring harness for proper connections, bent or broken pins, corrosion, loose wires, and proper routing.

- Ignition wires for proper routing, cracking, hardness, and tight connections at distributor, coil, and spark plugs.

- Electrical wiring and harness connections for tight fit, abrasions, breaks, etc. Ground connections must be clean and tight.

- Verify that components are properly installed and have not been modified or damaged. Ensure that any replaced components are correct for the application.

- Check for air or vacuum leaks around intake and exhaust manifolds, throttle body, air flow meter, and air induction hoses.

- Catalytic converter(s), muffler, exhaust pipes, brackets, and hangers for modification or damage.

- Engine coolant for proper level and mixture.

- Transmission fluid level and quality.

- Engine oil for proper level and quality.

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.

Safety Warning

Initial Inspection

Use the Manual With the Right Hardware

When to See a Mechanic

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