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09 f250 PO430 code

dave_dj1

dave_dj1

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Jackson NY
09 F250 with the 3 valve 5.4 with 153K, automatic. I just bought it from the original owner.
The CEL came on today, code is PO430 which is the catalyst system is not operating properly.

P0430 OBD-II Trouble Code: Catalyst System Efficiency Below Threshold (Bank 2)​

It has had a stumble which I believe is coming from the vvt when it's hot as in plowing, I only do 6 driveways.
I'll see if I can read anything with the Forscan I bought and have yet to use.
Could be plugs, injectors, VVT solenoid or plugged cat
Fordtechmakuloco on youtube is a very good Ford guy, he says that the injectors rarely fail so that is the last thing he looks at.
 
dave_dj1 said:
09 F250 with the 3 valve 5.4 with 153K, automatic. I just bought it from the original owner.
The CEL came on today, code is PO430 which is the catalyst system is not operating properly.

P0430 OBD-II Trouble Code: Catalyst System Efficiency Below Threshold (Bank 2)​

It has had a stumble which I believe is coming from the vvt when it's hot as in plowing, I only do 6 driveways.
I'll see if I can read anything with the Forscan I bought and have yet to use.
Could be plugs, injectors, VVT solenoid or plugged cat
Fordtechmakuloco on youtube is a very good Ford guy, he says that the injectors rarely fail so that is the last thing he looks at.
Click to expand...
If you have a decent scan tool that can graph live data, pull up the upstream and downstream o2 sensor voltages for both banks and graph them. Once engine is warmed up and in closed loop, the upstream sensor should switch back and forth between high (rich) and low (lean) and the downstream should remain relatively steady and stable. Graphing makes it easier to see.

If both upstream and downstream switch at roughly the same rate the catalyst on bank 2 has failed. 99% of the time a P0430 or P0420 is a failed converter.

No other codes present? Check mode 6 data for misfire counters on each cylinder and see if any are recorded. Spark plugs are due to be changed at this point as it is, but these are notorious for plugs breaking off in the head. Best trick I’ve heard for that is to leave the coil packs on one bank loose, get the engine as hot as you can, yank the coil packs and hit the plugs with a 1/2 air impact. Install new plugs and repeat for other bank. Gives the least chance of them breaking.
 
Last edited:
jimmy123456789 said:
If you have a decent scan tool that can graph live data, pull up the upstream and downstream o2 sensor voltages for both banks and graph them. Once engine is warmed up and in closed loop, the upstream sensor should switch back and forth between high (rich) and low (lean) and the downstream should remain relatively steady and stable. Graphing makes it easier to see.

If both upstream and downstream switch at roughly the same rate the catalyst on bank 2 has failed. 99% of the time a P0430 or P0420 is a failed converter.

No other codes present? Check mode 6 data for misfire counters on each cylinder and see if any are recorded. Spark plugs are due to be changed at this point as it is, but these are notorious for plugs breaking off in the head. Best trick I’ve heard for that is to leave the coil packs on one bank loose, get the engine as hot as you can, yank the coil packs and hit the plugs with a 1/2 air impact. Install new plugs and repeat for other bank. Gives the least chance of them breaking.
Click to expand...
No other codes on my cheap little reader
Plugs were supposedly done before I got the truck although it did sit for two years. I've probably put 1500 miles on since I bought it back in August or so.
 
jimmy123456789 said:
If you have a decent scan tool that can graph live data, pull up the upstream and downstream o2 sensor voltages for both banks and graph them. Once engine is warmed up and in closed loop, the upstream sensor should switch back and forth between high (rich) and low (lean) and the downstream should remain relatively steady and stable. Graphing makes it easier to see.

If both upstream and downstream switch at roughly the same rate the catalyst on bank 2 has failed. 99% of the time a P0430 or P0420 is a failed converter.

No other codes present? Check mode 6 data for misfire counters on each cylinder and see if any are recorded. Spark plugs are due to be changed at this point as it is, but these are notorious for plugs breaking off in the head. Best trick I’ve heard for that is to leave the coil packs on one bank loose, get the engine as hot as you can, yank the coil packs and hit the plugs with a 1/2 air impact. Install new plugs and repeat for other bank. Gives the least chance of them breaking.
Click to expand...
That's a lot of extra words to tell him to pull codes and throw parts at it.
 
X2 on what Jimmy123456789 said, I already know he's done this job plenty of times by what he said and he understands that data in a scanner.
I've done plenty of work on those engines and I couldn't said it better.

Projectjunkie said:
A 420 or 430 can be patched up with a resistor and a capacitor
Click to expand...
Can you elaborate on this? I've done the anti foulers trick before and I have seen I circuit board that creates the signal the PCM what's to see.
 
Gdogg said:
X2 on what Jimmy123456789 said, I already know he's done this job plenty of times by what he said and he understands that data in a scanner.
I've done plenty of work on those engines and I couldn't said it better.


Can you elaborate on this? I've done the anti foulers trick before and I have seen I circuit board that creates the signal the PCM what's to see.
Click to expand...


It's getting harder to find the info, but search "oxygen sensor desensitizer" the best info I found was in a yt video that might have been 4-5 min long

The ecm is looking for the rear sensors graph to be lower without spikes

You add the right capacitor to lower the graph, then you add the capacitor to smooth out the spikes. Once i used a variable capacitor to fine tune a picky one. Give the ecm the data it wants to see
 
Projectjunkie said:
The ecm is looking for the rear sensors graph to be lower without spikes

You add the right resistor to lower the graph, then you add the capacitor to smooth out the spikes. Once i used a variable capacitor to fine tune a picky one. Give the ecm the data it wants to see
Click to expand...

fixed
 
Projectjunkie said:
It's getting harder to find the info, but search "oxygen sensor desensitizer" the best info I found was in a yt video that might have been 4-5 min long

The ecm is looking for the rear sensors graph to be lower without spikes

You add the right capacitor to lower the graph, then you add the capacitor to smooth out the spikes. Once i used a variable capacitor to fine tune a picky one. Give the ecm the data it wants to see
Click to expand...
The PCM wants to see a flat line, if it sees the switching like on the front O2's then it know the converters aren't working.
There are over 60 codes for the O2's that are mandated by the EPA
 
Gdogg said:
The PCM wants to see a flat line, if it sees the switching like on the front O2's then it know the converters aren't working.
There are over 60 codes for the O2's that are mandated by the EPA
Click to expand...

It's not going to see a "flat line" off the showroom floor, it's going to see enough of a spread to tell the ecm that the cats are functional. Cats get tired, the spread gets too big, the voltage from rear o2 sensor gets too great, so you put a resistor inline, and the voltage drops to acceptable level, the ecm sees the spread it wants, no 420/430
 
Projectjunkie said:
It's not going to see a "flat line" off the showroom floor, it's going to see enough of a spread to tell the ecm that the cats are functional. Cats get tired, the spread gets too big, the voltage from rear o2 sensor gets too great, so you put a resistor inline, and the voltage drops to acceptable level, the ecm sees the spread it wants, no 420/430
Click to expand...
But is the cat functioning or is it going to be clogged and make it run like shit?
I don't need the truck plugged in here for inspections because it's 8800 gvrw but I do want it to run properly.
 
dave_dj1 said:
But is the cat functioning or is it going to be clogged and make it run like shit?
I don't need the truck plugged in here for inspections because it's 8800 gvrw but I do want it to run properly.
Click to expand...
Those codes don't affect drivability in my experience
DMG said:
Not on anything this new. Spark plug non-foulers will usually do it.
Click to expand...
I've done it as new as 06:homer:
 
So is FORscan an actual scanner? Or just a programmer? I can't seem to get it to do anything but tell me there is a code P0430 but not how to reset it.
 
dave_dj1 said:
So is FORscan an actual scanner? Or just a programmer? I can't seem to get it to do anything but tell me there is a code P0430 but not how to reset it.
Click to expand...
I don’t use it as a scanner but one of those plug-in old code readers will read and clear codes
 
DMG said:
I don’t use it as a scanner but one of those plug-in old code readers will read and clear codes
Click to expand...
I have two of those and yes I can read and clear the codes but I was hoping to be able to do some diagnostics with the FOR scan.
Oh well, not out much.
 
dave_dj1 said:
I have two of those and yes I can read and clear the codes but I was hoping to be able to do some diagnostics with the FOR scan.
Oh well, not out much.
Click to expand...
You should be able to look at sensor data with Forscan. Better do it quick before it warms up and the cats start working better.
 
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