Another 3.0 misfire
#26
#27
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P0430 Catalyst System Efficiency Below Threshold (Bank 2)
This would ONLY apply to V6 engine with DUAL EXHAUST system
Yes, it means that a Cat converter is most likely not working on the Drivers side exhaust system(bank 2), bank 1 is passenger side
The computer compares the upstream O2 sensor on that bank to the downstream O2 sensor, the down stream O2 should "see" very little oxygen if the Cats are working, if oxygen level stays high for too long then P0430
So this could also be cause by an exhaust leak after the upstream O2
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
This is the more common code for Rangers since most had single exhaust system, bank 1 and 2 exhaust was combined on a V6 with a "Y" pipe and exited down the passenger side of vehicle, so bank 1 side
4cyl also has exhaust on passenger side
Same reason for code, downstream O2 showing higher oxygen levels, from failing Cat or exhaust leak
Either can also be caused by failing downstream O2 sensor, but these rear O2s tend to last much longer than the front O2s
This would ONLY apply to V6 engine with DUAL EXHAUST system
Yes, it means that a Cat converter is most likely not working on the Drivers side exhaust system(bank 2), bank 1 is passenger side
The computer compares the upstream O2 sensor on that bank to the downstream O2 sensor, the down stream O2 should "see" very little oxygen if the Cats are working, if oxygen level stays high for too long then P0430
So this could also be cause by an exhaust leak after the upstream O2
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
This is the more common code for Rangers since most had single exhaust system, bank 1 and 2 exhaust was combined on a V6 with a "Y" pipe and exited down the passenger side of vehicle, so bank 1 side
4cyl also has exhaust on passenger side
Same reason for code, downstream O2 showing higher oxygen levels, from failing Cat or exhaust leak
Either can also be caused by failing downstream O2 sensor, but these rear O2s tend to last much longer than the front O2s
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B.aguilar (10-23-2020)
#28
P0430 Catalyst System Efficiency Below Threshold (Bank 2)
This would ONLY apply to V6 engine with DUAL EXHAUST system
Yes, it means that a Cat converter is most likely not working on the Drivers side exhaust system(bank 2), bank 1 is passenger side
The computer compares the upstream O2 sensor on that bank to the downstream O2 sensor, the down stream O2 should "see" very little oxygen if the Cats are working, if oxygen level stays high for too long then P0430
So this could also be cause by an exhaust leak after the upstream O2
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
This is the more common code for Rangers since most had single exhaust system, bank 1 and 2 exhaust was combined on a V6 with a "Y" pipe and exited down the passenger side of vehicle, so bank 1 side
4cyl also has exhaust on passenger side
Same reason for code, downstream O2 showing higher oxygen levels, from failing Cat or exhaust leak
Either can also be caused by failing downstream O2 sensor, but these rear O2s tend to last much longer than the front O2s
This would ONLY apply to V6 engine with DUAL EXHAUST system
Yes, it means that a Cat converter is most likely not working on the Drivers side exhaust system(bank 2), bank 1 is passenger side
The computer compares the upstream O2 sensor on that bank to the downstream O2 sensor, the down stream O2 should "see" very little oxygen if the Cats are working, if oxygen level stays high for too long then P0430
So this could also be cause by an exhaust leak after the upstream O2
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
This is the more common code for Rangers since most had single exhaust system, bank 1 and 2 exhaust was combined on a V6 with a "Y" pipe and exited down the passenger side of vehicle, so bank 1 side
4cyl also has exhaust on passenger side
Same reason for code, downstream O2 showing higher oxygen levels, from failing Cat or exhaust leak
Either can also be caused by failing downstream O2 sensor, but these rear O2s tend to last much longer than the front O2s
#29
Okay well I got the extra bolt and I put it on, I got it from the junkyard. I still have a slight tick and I assume it’s an exhaust leak somewhere on the manifolds because I still have the codes before. But today was something different I got a code for both banks 1 and 2 p0147 and p0171. As well as a misfire detected on the first something revolutions don’t remember exactly what it said. And the last code was a misfire detected on cylinder 5. What do I do? It sounds healthy besides the tick. And a slight rough idle. I’m at a loss I don’t know what to do.
#30
Okay well I got the extra bolt and I put it on, I got it from the junkyard. I still have a slight tick and I assume it’s an exhaust leak somewhere on the manifolds because I still have the codes before. But today was something different I got a code for both banks 1 and 2 p0147 and p0171. As well as a misfire detected on the first something revolutions don’t remember exactly what it said. And the last code was a misfire detected on cylinder 5. What do I do? It sounds healthy besides the tick. And a slight rough idle. I’m at a loss I don’t know what to do.
Exhaust leaks, closer to that O2S, ate notorious for causing such lean conditions also.
Unmetered air getting into the engine, through other areas of the engine, with going straight to the MAF sensor is another area you have to look at.
Putting some seafoam in the fuel system might clear the gunk in the injectors and fuel system maybe when you try it out.
The misfire on cylinder #5, maybe related to either the coils, spark plugs, or piston ring on that cylinder has issues.
What's d mileage on the odometer?
Last edited by Toyota XLT; 10-25-2020 at 11:13 PM.
#31
The mileage is about 253k but I replaced heads and gaskets on it cause of leaking exhaust valves. I was told the piston rings were good. But that’s why I assume I have a exhaust leak somewhere near the manifold that’s causing the O2s to read rich in oxygen giving more fuel causing the misfire? When I drive it I don’t feel a misfires and it doesn’t idle that rough like a misfire would do. And the ticking noise is greater when I accelerate when I let go of the gas and coast it fades away. And I’ve changed the spark plugs recently and I’ve changed the coil pack and plugs.
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chrispinzon22
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08-25-2019 12:46 PM