99 Toyota

CHUCK38

MEMBER
1999 TOYOTA

Engine sounds like it has excessive back pressure. Car will not operate above 3000 RPM. Engine will not pull car on any hill. But once car is going it will maintain speed until another hill. Also power brakes are out but have fluid. 4 cyl 120,000

1 Reply

RASMATAZ

MECHANIC
75,992 POSTS

For power Check the exhaust for restriction ( Cat )/coolant temperature and oxygen sensors. For the brake, check the vacuum hose/check valve to the booster for a start.

Here's some more on the O2 sensor:

With engine OFF, connect the negative lead of the DVOM to engine ground. Set the DVOM to read DC VOLTS. Disconnect the oxygen sensor (O2S) electrical connector and connect the positive lead of the DVOM to the oxygen sensor signal wire.

Start engine. Create a lean condition, disconnect a vacuum line for 10 seconds. Voltage should decrease to 0.2 volt or less and remain there.

Create a rich condition, shoot some carburetor cleaner into the throttle body, for 10 seconds. Voltage should increase to 0.8 volt or more and remain there.

If sensor fails to vary according to the test steps above, the sensor is defective.
Connect sensor and clear codes.