Loading ...
Loading ...
Loading ...
DTC P0420 THREE WAY CATALYST FUNCTION
EC-269
[QR (WITH EURO-OBD)]
C
D
E
F
G
H
I
J
K
L
M
A
EC
7. Make sure that the voltage switching frequency (high & low)
between ECM terminal 16 and ground is very less than that of
ECM terminal 35 and ground.
Switching frequency ratio = A/B
A: Heated oxygen sensor 2 voltage switching frequency
B: Heated oxygen sensor 1 voltage switching frequency
This ratio should be less than 0.75.
If the ratio is greater than above, it means three way catalyst
does not operate properly. Go to EC-269, "
Diagnostic Proce-
dure" .
NOTE:
If the voltage at terminal 35 does not switch periodically more than 5
times within 10 seconds at step 7, perform trouble diagnosis for DTC P0133 first. (See EC-189, "
DTC P0133
HO2S1" .)
Diagnostic Procedure BBS001EC
1. CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst (manifold).
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK IGNITION TIMING
Check the following items. Refer to EC-82, "
Basic Inspection" .
MBIB0124E
SEC502D
Items Specifications
Target idle speed
QR20DE with M/T models 650 ± 50 rpm (in Neutral position)
Except above 700 ± 50 rpm [in P or N (A/T), Neutral (M/T) position]
Ignition timing 15 ± 5° BTDC [in P or N (A/T), Neutral (M/T) position]
Loading ...
Loading ...
Loading ...