2003-2008 Toyota Corolla R & R Intake Manifold Gasket

Following a cold soak in subfreezing ambient temperatures, some 2003 – 2008 model year Corolla and Matrix vehicles equipped with a 1ZZ–FE engine may exhibit a M.I.L. “ON” with one or more of the following Diagnostic Trouble Codes (DTCs) as the result of a vacuum leak at the intake manifold.
S P0171 – System Too Lean (Bank 1)
S P0300 – Random Multiple Cylinder Misfire Detected
S P030# – Cylinder (1–4) Misfire Detected
S P0133 – Oxygen Sensor Slow Response (Bank 1 Sensor 1)
Please use the following procedure to repair the vehicle.

The vehicle MUST be diagnosed following a cold soak. If the vehicle is at operating temperature, the condition will NOT be present.
1. Monitor the following Data List parameter: Short FT #1 (Short Term Fuel Trim for Bank 1). Using TIS techstream, select: Connect to Vehicle/Engine and ECT/Data List/Short FT #1.
2. Following conventional diagnostic procedure, confirm if there is a leak where the intake manifold and cylinder head meet between each intake runner.
3. Did the short term fuel trim change to a rich reading (negative fuel trim) in step 2?
S If YES — Replace the intake manifold gasket.
S If NO — Check for other vacuum leaks or lean running conditions per the Technical Information System (TIS).

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