Hi everyone, am new here.
My car details; 2005 4runner SRS5 4WD V8 4.7L 84,570 miles, presently VSL trac/trac off & maintenance light came up on dash board. I checked the codes and got P0420 & P0430 Codes, I was thinking of changing the four o2 sensors but a mechanic recommends that I should try catalyst bypass.
Also the fuel consumption is extremely bad.

the codes are indicating that you have insufficient O2 sensor readings..

the O2 sensor on bank one up stream is reading the same as the 02 sensor down stream which is telling the computer that the catalytic converter isnt working properly..

it could be the catalytic converters, however if theres any exhaust leaks from your manifolds before the catalytic converters this will cause a faulty reading as well.

check for exhaust leaks first.. with the engin running and the hood up listen for ticking noises comeing from the left of right side of the engine..

if no exhaust leaks are present check the voltage readings of the 02 sensors to make sure there functioning properly..

If the 02 sensors check out and theres no exhaust leaks then you'll need to replace the catalytic converters...

hope this helps..
you can also google the trouble codes and get a generic idea of what the codes are pertaining to.

the p0420 is you driver side 02 sensor/ catalytic converter (bank 1)
the p0430 is the passenger side.. (bank 2)

you havn't by chance gotten ahold of leaded fuel by chance that can cause this issue as well. or running really bad gas as well.

Am not based in US, am sure fuel being sold here is not leaded fuel.
I will also check for exhaust leaks and keep you posted.

Not sure what country you're in, but I think we have an 8 year emissions warranty in the US. You might see if there is some similar regulation in your country.

My major concern are the codes and the car fuel consumption is extremely bad.

I did checked the exhaust yesterday, everything seems fine.

just put some long tube headers with a o2 simulator on it and you wont have to worry about replacing such expensive items

is this the same as catalyst bypass?

Yes.

You need the simulator to "fool" the car into thinking all is well.

What country are you in? Crappy gas?

Am in Nigeria, can you enlighten me more concerning catalyst bypass. I hope it wont have affect the performance of the car in the long run.

Fuel consumption is terrible at the moment.

I was able to use Actron CP9580 to check the car, I know this is tending towards replacing the CAT's, can anyone explain better what the data below means;

2005 Toyota 4-Runner 4.7

I/M Monitors

Since DTCs Cleared

Misfire Monitor ok
Fuel System Mon ok
Comp Component ok
Catalyst Mon inc
Htd Catalyst n/a
Evap System Mon ok
Sec Air System ok
A/C Refrig Mon n/a
Oxygen Sens Mon inc
Oxygen Sens Htr n/a
EGR System Mon n/a

---------------------

This Drive Cycle

Misfire Monitor ok
Fuel System Mon ok
Comp Component ok
Catalyst Mon n/a
Htd Catalyst n/a
Evap System Mon inc
Sec Air System n/a
A/C Refrig Mon n/a
Oxygen Sens Mon n/a
Oxygen Sens Htr n/a
EGR System Mon n/a

=====================

DTCs (Codes)

P0420 MOD $00

Catalyst System Efficiency Below
Threshold Bank 1

PENDING

TOP REPORTED FIX
1-Replaced Catalytic
Converter

FREQ REPORTED FIX
1-Replaced Oxygen
(O2) Sensor

ALSO REPORTED FIX
1-Replaced Catalytic
Converter Gasket

---------------------

P0430 MOD $00

Catalyst System Efficiency Below
Threshold Bank 2

PENDING

FREQ REPORTED FIX
1-Replaced Catalytic
Converter

=====================

State OBD Check

MIL Status OFF
Codes Found 0
Monitors OK 5
Monitors Inc 2
Monitors N/A 4

=====================

Record Data

FRAME: -1 TM: -4.6

MIL STATUS Off
ABSLT TPS(%) 19.6
ENG SPEED(RPM) 0
BARO PRS("HG) 29.5
CALC LOAD(%) 0.0
MAF(LB/M) 0.20
COOLANT(°F) 201
IAT(°F) 169
IGN ADV(°) 5.0
SECOND AIR N/A
ST FTRM1(%) 0.0
LT FTRM1(%) 7.0
ST FTRM2(%) 0.0
LT FTRM2(%) 10.9
VEH SPEED(MPH) 0
ABS LOAD(%) 0.0
FUEL SYS 1 OPEN
FUEL SYS 2 OPEN
REL TPS(%) 0.4
THROT CMD(%) 16.5
ABS TPS B(%) 51.8
ACC POS D(%) 15.7
ACC POS E(%) 31.8
CAT TEMP11(°F) 996
CAT TEMP21(°F) 996
CAT TEMP12(°F) 746
CAT TEMP22(°F) 746
EVAP PURGE(%) 0.0
ABS EVAP VP(H2O)403.2
CMD EQ RAT 0.824
O2S12(V) 0.015
O2S22(V) 0.015
O2S11(V) 4.001
EQ RATIO11 1.000
EQ RATIO21 1.000
O2S21(V) 4.002
MIL TIME(h:m) 00:00
CLR DIST(mi) 26
CLR TIME(h:m) 05:32
CLR TRPS 3
MIL DIST(mi) 0
VPWR(V) 12.226
ENG RUN(m:s) 00:00
OBD2 STAT CA

2005 Toyota 4-Runner 4.7

O2 Monitor Tests

Not Supported by Vehicle

2005 Toyota 4-Runner 4.7

Diag Monitor Tests

O2 Sensor B1S1

Test $8E
MOD $00
MAX 0.000(V)
MEAS 0.000(V)
MIN 0.000(V)
STS OK

Test $91
MOD $00
MAX 0.000(mA)
MEAS 0.000(mA)
MIN 0.000(mA)
STS OK

---------------------

O2 Sensor B1S2

Min V for Cycle
MOD $00
MAX 0.195(V)
MEAS 0.097(V)
MIN 0.000(V)
STS OK

Max V for Cycle
MOD $00
MAX 1.190(V)
MEAS 0.859(V)
MIN 0.605(V)
STS OK

Test $8F
MOD $00
MAX 2.998
MEAS 0.007
MIN 0.000
STS OK

---------------------

O2 Sensor B2S1

Test $8E
MOD $00
MAX 0.000(V)
MEAS 0.000(V)
MIN 0.000(V)
STS OK

Test $91
MOD $00
MAX 0.000(mA)
MEAS 0.000(mA)
MIN 0.000(mA)
STS OK

---------------------

O2 Sensor B2S2

Min V for Cycle
MOD $00
MAX 0.195(V)
MEAS 0.078(V)
MIN 0.000(V)
STS OK

Max V for Cycle
MOD $00
MAX 1.190(V)
MEAS 0.898(V)
MIN 0.605(V)
STS OK

Test $8F
MOD $00
MAX 2.998
MEAS 0.001
MIN 0.000
STS OK

---------------------

Catalyst B1

Test $A9
MOD $00
MAX 9.994
MEAS 0.005
MIN 0.039
STS LOW

---------------------

Catalyst B2

Test $A9
MOD $00
MAX 9.994
MEAS 0.005
MIN 0.039
STS LOW

---------------------

Purge Flow Mon

Test $C9
MOD $00
MAX 4.752(PSI)
MEAS 0.026(PSI)
MIN 0.000(PSI)
STS OK

Test $CA
MOD $00
MAX 4.752(PSI)
MEAS 0.348(PSI)
MIN 0.000(PSI)
STS OK

Test $CB
MOD $00
MAX 4.752(PSI)
MEAS 0.217(PSI)
MIN 0.000(PSI)
STS OK

Test $CD
MOD $00
MAX 4.752(PSI)
MEAS 0.217(PSI)
MIN 0.000(PSI)
STS OK

Test $CE
MOD $00
MAX 4.752(PSI)
MEAS 0.316(PSI)
MIN 0.000(PSI)
STS OK

Test $CF
MOD $00
MAX 4.752(PSI)
MEAS 0.233(PSI)
MIN 0.000(PSI)
STS OK

Test $D0
MOD $00
MAX 4.752(PSI)
MEAS 0.329(PSI)
MIN 0.000(PSI)
STS OK

Test $D1
MOD $00
MAX 4.752(PSI)
MEAS 0.217(PSI)
MIN 0.000(PSI)
STS OK

Test $D4
MOD $00
MAX 4.752(PSI)
MEAS 0.354(PSI)
MIN 0.000(PSI)
STS OK

Test $D5
MOD $00
MAX 4.752(PSI)
MEAS 0.348(PSI)
MIN 0.000(PSI)
STS OK

Test $D7
MOD $00
MAX 4.752(PSI)
MEAS 0.000(PSI)
MIN 0.000(PSI)
STS OK

---------------------

Sec Air Mon 1

Test $E1
MOD $00
MAX 86.51(LB/M)
MEAS 0.63(LB/M)
MIN 0.27(LB/M)
STS OK

Test $E2
MOD $00
MAX 0.72(PSI)
MEAS 0.02(PSI)
MIN 0.00(PSI)
STS OK

Test $E3
MOD $00
MAX 95.05(PSI)
MEAS 1.14(PSI)
MIN 0.14(PSI)
STS OK

Test $E4
MOD $00
MAX 2.90(PSI)
MEAS 0.04(PSI)
MIN 0.00(PSI)
STS OK

Test $E5
MOD $00
MAX 95.05(PSI)
MEAS 7.59(PSI)
MIN 2.35(PSI)
STS OK

Test $E6
MOD $00
MAX 2.90(PSI)
MEAS 0.03(PSI)
MIN 0.00(PSI)
STS OK

Test $E7
MOD $00
MAX 95.05(PSI)
MEAS 2.01(PSI)
MIN 0.75(PSI)
STS OK

Test $E8
MOD $00
MAX 95.05(PSI)
MEAS 0.31(PSI)
MIN 0.23(PSI)
STS OK

Test $E9
MOD $00
MAX 0.00(PSI)
MEAS 0.00(PSI)
MIN 0.00(PSI)
STS OK

---------------------

Misfire Data

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 1

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 2

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 3

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 4

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 5

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 6

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 7

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Misfire Cyl 8

EWMA Misfire Cnt
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

Misfire Cnt Last
MOD $00
MAX 65535(cnts)
MEAS 0(cnts)
MIN 0(cnts)
STS OK

---------------------

Monitor $E1

Test $E8
MOD $00
MAX 5930.1(°F)
MEAS 167.0(°F)
MIN 167.0(°F)
STS OK


2005 Toyota 4-Runner 4.7

Vehicle Information

VIN

#1 MOD $00: JTEBT14R058027606

CVN

#1 MOD $00: D1 9B F0 A1

CAL ID

#1 MOD $00: 33532200

IPT

#1 MOD $00:
OBD Mon Cond 5
Ignition Cycles 31
Cat Comp Bank1 7
Cat Cond Bank1 5
Cat Comp Bank2 7
Cat Cond Bank2 5
O2 Comp Bank1 2
O2 Cond Bank1 5
O2 Comp Bank2 2
O2 Cond Bank2 5
EGR Mon Comp Not Available
EGR Mon Cond 5
AIR Mon Comp 9
AIR Mon Cond 1
EVAP Mon Comp 2
EVAP Mon Cond 1


Also how many Cat's does the car have?

Ooh Mode $06 Data! You don't see too many people using that these days (hell, I don't play with Mode $06 very much myself, but I'll try and answer best I can.) Unfortunetly our factory TIS TechStream doesn't use Mode $06 (at least not that I found easily) so I'm not 100% sure how accurate the results are. But I highlighted the points I would look at.

There are 4 Catalytic converters on your vehicle, 2 are integrated into the exhaust manifolds.

If am to change anything, what do u suggest?

If am to change anything, what do u suggest?
Do I have to change the front 2 Cats or all the 4 Cats.

I had same problem. Here is what I did.

Replaced O2 sensors all 4 of them. Did not work.


spent $1600 replacing two cat converters. Worked.


My cat converters die at around 130,000 (check engine light popped). Cat held until around 180,000.
Cat converter lifespan is around 120,000 ~ 190,000 miles under normal maintenance. (change O2 sensors at 50,000 miles interval will prolong Cat converter lifespan)

My 04 4runner SR5 has 250,000 miles on its clock. No major problems except wear and tear parts replacement.

I wouldn't worry about the PO420 unless you have to pass emissions.

I've had PO420 for over a year now and the cause was cutting my back 2 cats out. The car runs fine and does not hinder performance at all.

But that's just me because my county does not have emissions testing and I just clear the code with my scan gauge whenever it pops up.