Toyota 25052-20100 Exhaust Manifold Converter Sub-Assembly, No.2

1. Connect a vacuum gauge to an intake manifold vacuum source. 2. Warm the engine to operating temperature, place the transaxle in Park, and apply the parking brake. 3. Note and record the vacuum reading at idle. 4. Quickly open the throttle to near full throttle and release it shut, then note and record the vacuum reading. 5. Perform the test three more times, recording the reading after each test. 6. If the reading after the fourth test is more than one in-Hg lower than the idle reading, the exhaust system may be restricted, indicating that the catalytic converter could be plugged or that an exhaust pipe or muffler could be restricted.

Disconnect the electrical connector from the oxygen sensor at each manifold.