DEFINITION: The engine delivers less than the expected power. There is little or no increase in the speed when the accelerator pedal is pushed down part way.

Did you perform the On-Board Diagnostic (OBD) System Check?

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Go to Step 2

Go to the Powertrain On Board Diagnostic (OBD) System Check

1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is present, correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom?

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Go to Step 17

Go to Step 3

Did you perform a visual/physical check?

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Go to Step 4

Go to Symptoms for the Visual /Physical Check

1. Remove and check the air filter element for dirt or for a restriction.
2. Replace the air filter element if necessary.

Was a repair required?

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Go to Step 16

Go to Step 5

Check the intake plenum switchover valve and the intake resonance switchover valve for proper operation. Refer to DTC P1112 Intake Plenum Switchover Solenoid Control Circuit and DTC P1113 Intake Resonance Switchover Solenoid Control Circuit .

Was a problem found and corrected?

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Go to Step 16

Go to Step 6

1. Check the fuel pressure. Refer to Fuel System Diagnosis .
2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 7

1. Check for water or alcohol contaminated fuel using a J 39383-A, gasoline test kit.
2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 8

1. Use a scan tool in order to monitor the knock retard for excessive spark retard activity.
2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 9

1. Remove the spark plugs. Check for the following conditions:

•

Wet plugs

•

Cracks

•	Excessive wear

•	An improper gap

•	Burned electrodes

•	Carbon tracking on the insulator

•	Heavy deposits, refer to Ignition System Check .

Notice: Determine the cause of the oil or gas fouled spark plugs in order to avoid damage to the new spark plugs.

2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 10

1. Check the ignition coils for cracks or carbon tracking.
2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 11

1. Check the ECM grounds for being clean, tight and in the proper locations.
2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 12

1. Check the exhaust system for a possible restriction:

•	Inspect the exhaust system for any damaged or collapsed pipes.

•	Inspect the muffler for heat distress or a possible internal failure.

•	Check for a possible plugged catalytic converter by checking the exhaust system back pressure. Refer to Restricted Exhaust System Check .

2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 13

1. Check the torque converter clutch (TCC) for a proper operation. Refer to Torque Converter Diagnosis .
2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 14

1. Check for the following Engine Mechanical problems. Refer to Engine Mechanical:

•	Low compression

•	Sticking valves

•	A hydraulic valve lifter problem

•	Leaking cylinder head gaskets

•	Worn or incorrect camshaft

•	Incorrect cam timing

•	A damaged timing belt

2. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 15

1. Review all of the diagnostic procedures within this table.
2. When all of the procedures have been completed and no malfunctions are present, review/inspect the following items:

•	The scan tool data

•	The Freeze Frame data

•	All of the connections within a suspected circuit and/or system

3. If a problem is present, repair as necessary.

Was a problem found?

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Go to Step 16

Go to Step 3

Operate the vehicle under the same conditions (as closely as possible) as when the original symptom occurred.

Is the original symptom still present?

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Go to Step 3

Go to Step 17

Are any other driveability symptoms still present?

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Go to Symptoms

System OK