Visually/physically inspect the air leakage in intake/exhaust system for the following areas:

▶ Vacuum hoses for splits, kinks and improper connections.

▶ Throttle body gasket

▶ Gasket between intake manifold and cylinder head

▶ Seals between intake manifold and fuel injectors

▶ Exhaust system between HO2S and three way catalyst for air leakage

Has a problem found in this procedure?

	▶ Repair or replace as necessary. Go to "Verification of Vehicle Repair" procedure.
	▶ Go to next step as below.

Remove the manifold side vacuum hose from the EVAP canister purge valve.

Using a hand vacuum pump apply specified vacuum(Approx. 15 in, Hg) to the manifold side of the valve.

Does the valve hold vacuum?

	▶ Go to next step as below.
	▶ Repair or replace as necessary. Go to "Verification of Vehicle Repair" procedure.

Visually/physically inspect the front HO2S for the following conditions:

▶ Ensure that the HO2S is securely installed.

▶ Silicon contamination. This contamination will be indicated by a white powdery coating on the portion of the sensor exposed to the exhaust stream and this will result in a but false(high) voltage signal

▶ Fuel, engine coolant or oil contamination

▶ Use of improper sealant

▶ If contamination is evident on the HO2S, Fix the source of the sensor contamination before replacing the sensor to prevent future contamination. Go to "Verification of Vehicle Repair" procedure.

Visually/physically inspect the MAFS for the following conditions:

▶ Contamination or deterioration

▶ Poor connection or damaged harness

Check for an intermittent TPS1 false signal. TPS1 signal displayed on a scantool should increase steadily when depressing accelerator pedal after starting.

Verify that the PCM/ECM ground connections are clean and properly tightened.

If test result is NG, repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.If OK, go to next step as below.

Check the engine oil level. The oil level should be between the min. and max. marking. Fill to the correct oil level.

Check crankcase ventilation valve for improper installation, damaged o-rings and malfunctioning.

Warm up the engine to normal operating temperature.

Connect Scantool and note the "SHORT TERM FUEL-B1" parameter on the Scantool data list.

Disconnect and plug the positive crankcase ventilation at the intake manifold side.

Monitor the "SHORT TERM FUEL-B1" parameter on the Scantool data list once again.

Is the displayed value within the specified value?

	▶ Go to next step as below.
	▶ Check the PCV(Positive Crankcase Ventilation) valve for operation properly. Refer to "EM" group in Workshop Manual. If OK, check that engine oil is diluted with fuel. Change the oil or filter as necessary and go to "Verification of Vehicle Repair" procedure.

Check the fuel for excessive water, alcohol, or other contaminants. Replace contaminated fuel as necessary.

Install a fuel pressure gage.

Inspect fuel pressure with normal idle status.

Is fuel pressure within the specified value?

	▶ Go to next step as below.
	▶ Inspect the suspected area. Refer to table as below. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

Stop the engine and check for a change in the fuel pressure gauge reading.

Is fuel pressure within the specified value?

	▶ Go to next step as below
	▶ Inspect the suspected area. Refer to table as below. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.