Mazda RX-8 Manual page 683

VERIFY CURRENT INPUT SIGNAL
STATUS OF REAR HO2S
Connect the WDS or equivalent to the
•
DLC-2.
Start the engine and warm it up
•
completely.
Access the O2S12 PID.
•
Read the O2S12 PID under following
•
accelerator pedal conditions (in PARK or
NEUTRAL).
More than 0.55 V when
suddenly depress accelerator
pedal (rich condition).
Less than 0.55 V just after
release of accelerator pedal (lean
condition).
Is the PID normal?
•
INSPECT INSTALLATION OF REAR HO2S
6 Inspect the rear HO2S for looseness.
•
Is it normal?
•
INSPECT EXHAUST SYSTEM FOR
EXHAUST GAS LEAKAGE
7
Visually inspect exhaust gas leakage in
•
the exhaust system.
Is there exhaust gas leakage?
•
INSPECT LONG TERM FUEL TRIM
Connect the WDS or equivalent to the
•
DLC-2.
Access the LONGFT1 PID.
•
8
Compare the LONGFT1 PID with
•
recorded FREEZE FRAME DATA at
Step 1.
Is the LONGFT1 PID below FREEZE
•
FRAME DATA?
INSPECT FUEL LINE PRESSURE
9
(EXCESSIVE FUEL LINE PRESSURE)
No Go to the next step.
Yes Go to the next step.
Tighten the rear HO2S, then go to Step 14.
No
(See REAR HEATED OXYGEN SENSOR
(HO2S) REMOVAL/INSTALLATION .)
Repair or replace the malfunctioning part, then
Yes
go to Step 14.
Replace the rear HO2S, then go to Step 14.
No
(See REAR HEATED OXYGEN SENSOR
(HO2S) REMOVAL/INSTALLATION .)
Engine is driven under rich condition.
Yes
Go to the next step.
Engine is driven under lean condition.
No
Go to Step 10.
Repair or replace the malfunctioning part
according to the inspection results.
Yes
Then go to the Step 14.
(w) Engine Diagnostics & Control
Page 120