Toyota Corolla (E120): Engine
On–vehicle inspection
Hint
: inspect these items on a cooled down engine.
1. Inspect drive belt
2. Replace spark plugs
3. Inspect air filter

- Remove the air filter.
- visually check that the air filter is not excessively damaged,
dirty or oily.
Peplace the air filter if necessary.
- clean the filter with compressed air.
First blow from the inside of the filter thoroughly then repeat from the outside.
- reinstall the air filter.
4. Replace air filter
- replace the air filter with a new one.
5. Replace engine oil and oil filter
6. Replace engine coolant
7. Inspect gasket in fuel tank cap
8. Inspect fuel lines and connections, fuel tank vapor vent system hoses and fuel tank bands
- visually check the fuel lines for cracks, leakage, loose connections, deformation and tank band looseness.
9. Inspect exhaust pipes and mountings
- visually check the pipes, hangers and connections for severe corrosion, leaks and damage.
10. Inspect valve clearance
Other materials:
Diagnostic trouble code chart
The inspection procedures are shown in the table below. This table allows
efficient and accurate troubleshooting
using the diagnostic trouble codes displayed in the diagnostic trouble code
chart. Proceed with
troubleshooting in accordance with the inspection procedures listed in the
diagnost ...
Circuit description
The ecm compares the two waveforms of the heated oxygen sensors located
before and after the catalyst
to determine whether or not the catalyst performance has deteriorated.
Air–fuel ratio feedback compensation keeps the waveform of the heated oxygen
sensor in front of the catalyst
alterna ...
Do-it-yourself service precautions
If you perform maintenance by yourself, be sure to follow the correct procedure
as given in these sections.
CAUTION
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energized. To avoid death or serious injury,
observe t ...


