It is possible that your car is not equipped. As I recall, not all ES's had the filter but if you do, the previous instructions are correct. If not, there will not be the tab to remove as he referred.
Check for a bad or lazy main o2 sensor by reading the voltages. Check for air leaking into the intake downstream of the air flow meter. Like the vacuum hoses from the P/S pump. Just ideas! Hope this helps.
Diag Code
25 Air–Fuel Ratio Lean Malfunction
Diag. 26 Air–Fuel Ratio Rich Malfunction
CIRCUIT DESCRIPTION
Refer to page TR–38 for the circuit description.
Code No. Diagnosis Trouble Area
1*1. The conditions (a) and (B) below are
detected once, then are established
again after the ignition switch is turned
from OFF to ON.
(a) The engine is warmed up and is in
a high load condition at an engine
rpm higher than 1500 rpm.
(B) The main oxygen sensor signal
stays lean for a set period of time
or longer.
Harness or connector between ECU
and main oxygen sensor.
Main oxygen sensor.
Fuel line pressure.
Ignition system.
Air intake system.
Injector circuit.
Water temp. sensor.
Intake air temp. sensor.
ECU
25
26
Normal Mode
2*2. When air–fuel ratio feedback compensation
value feedback frequency is
abnormally high during idle switch on
and feedback condition.
3*3. When the difference of air–fuel ratio
feedback compensation value between
right and left banks is more than
a certain percentage.
Code 25 displayed :
Deviation to lean side with the
difference more than a certain
percentage.
Code 26 displayed :
Deviation to rich side with the
difference more than a certain
percentage.
Codes 25 and 26 displayed:
Deviation to rich or lean side with
the difference less than a certain
percentage.
Fuel line pressure.
Air intake system.
Injector circuit.
Ignition system.
Cold start injector circuit.
Water temp. sensor.
Intake air temp. sensor.
ECU
Test