P0430 after new cats, O2’s, and spark plugs. 2013 F150 5.0

Having a hard time trying to figure this out!

-New cats for both banks
-New O2’s
-New spark plugs
-New MAF sensor
-negative LT fuel trims both banks -7% to -14%
-O2 voltage .75 both banks
-Airflow reads between 4-5 g/s at idle but sometimes climbs to 6.5 g/s
-can feel misfires especially when parked after driving

MIL indicates P0430
Took it to the shop and was told I needed a new cat. I decided to go ahead and replace both cats with Magnaflows. Guy at muffler shop scanned codes before making any repairs and was now showing P0430 and P0420.

After new cats were welded on, codes were cleared. P0430 came back on after about 100 miles.

I then replaced all O2’s and spark plugs with Bosch brand parts. Reset codes. Still P0430.

Took my truck back to shop and was told I had small misfire count on cylinder 5 which is bank 2. Replaced ignition coil. Guy said if it wasn’t that he didn’t know what it could be. P0430 came back.

Started doing my own research. Bought OBD2 scanner and I’ve been trying to make sense of the data along with developing symptoms.

-P0430
-P0300 - this code was thrown as pending 14 seconds after startup one morning but then disappeared. Haven’t had it appear since then.
But I check for misfires w/ scanner and show low counts for random cylinders each time. I can feel the misfires when at idle, especially after driving to work and putting in park.
-Fuel Trims - for both banks LTFT is running negative. Like anywhere between -7% to -14%, especially after I’ve been driving for a while (like 15-20 min). But STFT and LTFT read +/- 3% when I first start driving.
-airflow reads between 4-5g/s at idle. Got as high as 6g/s after I changed the MAF sensor but still reads 4-5 most times.
-O2 voltage for both banks is around .75

All signs point to rich condition if I’m not mistaken. But why? And why no codes for misfires and/or rich condition? Just P430 and felt misfires.

Any help is appreciated!

The misfires may have to be pretty consistent to set a code for them. Maybe a certain amount of consecutive misses. It could be something in the hundreds.

The fuel trims don't appear to be off enough to set a code for a rich condition if you look at the sum of LT and ST. In my experience, this total has to be in the 20%s to code.

For the converter codes, I've never used a magnaflow cat. Are these weld in options? Are they federal or carb compliant? Is your vehicle carb or federal compliant? It may just be that there's not enough magic material for the truck to be happy with them on, but others can chime in who have used them.

Do the trims change if you pinch off the purge line?

P0300 means that a miss is detected, but it's not sure which cylinder it's on. Are you looking at mode 6 to determine where the counts are setting? Keep in mind that this is not 100% accurate, so you'd want to be able to prove that the cylinder you're after is actually the one missing.

Watch the ignition timing, when behaving and not, curious to see if it's retarded when acting up

Pretty much everything Matt said.
Changing cats for cat codes without finding the cause is an expensive gamble. (Strike one for the repair shop). Even if the cats are perfectly fine, if they are being fed an incorrect air fuel mixture, they cannot function as designed and will likely reset the same codes, and eventually ruin your new cats.
Misfires will certainly cause this, and while ignition coils can be the cause of a misfire, there are MANY more factors (strike two for mentioned repair shop).
The simplest thing you could try in my opinion is an oil change and Keep Alive Memory (KAM) reset.
The reasoning being that misfiring can cause fuel contamination in the oil, which the PCV system will be breathing into the engine, resulting in negative fuel trims.
Ford fuel trims do not always correct after a repair, so a KAM reset is required. If your scanner doesn't support this functional test, disconnecting the battery and connecting the cables to each other for a few minutes will do the trick.
It's also important to note that fuel trims are dynamic, meaning they will change under different operating conditions. These conditions are important to note (warm idle, steady cruise, high load etc.) in order to get the full picture of the failure and to come up with an effective test plan.

The P0430 maybe the effect rather than the cause. You seem to have a true rich condition. A fuel delivery problem is most likely. Faulty or failing fuel regulator, fuel pump, leaking fuel injector. If you can, move the fuel injector from #5 to #1 cylinder. Does the misfire move to #1? Depending on the tools you have available other tests can be done.

Thank you guys for the responses.

A couple things I should clarify:

STFT is around -3%
LTFT is around -7 to -14%

The misfire is random. But mechanic mentioned no. 5 so we went with the new coil. After researching on my own began leaning towards problem with fuel input. Also started scanning for myself which is when I noticed the random misfires. I think I may need to upgrade my scanner to see a live count rather than just a snapshot. But I can definitely feel the misfires when in park after driving. I was leaning towards fuel injectors possibly leaking. But I don’t think I can switch them around in order to tell unless I get a better scanner.

And then the truck itself drives weird. It’s progressively getting worse. Losing power it seems like. Engine revs higher than it used to when under load.

My scanner can “clear codes” but is that considered a KAM reset?

I’ve taken note of freeze frame data several times after DTC shows up after clearing. Readings differ slightly depending on how I was driving. But all still within the same range and pointing in the same direction. Fuel trims way negative. O2 voltage above .7. Lambda like .85-.9. Fuel trims have been as low as ST -14, LT -10 for both banks.

Thanks again for everyone’s time!

I like Noah's suggestion to change the oil first. And see where you're at.

Just got a BlueDriver scanner today. Hopefully I can get some more useful info out of it.

I will try oil change and KAM reset and post what I find. Can’t say I’m all that optimistic tho…

Thanks for the responses!

rscar26 wrote:

Just got a BlueDriver scanner today. Hopefully I can get some more useful info out of it.

I will try oil change and KAM reset and post what I find. Can’t say I’m all that optimistic tho…

Thanks for the responses!

It might not help at all, but it's cheap and simple and it's where I would start if I took it over in my bay to know that I'm at least starting at a good base line.
Let us know how you make out.

If you want, you could record some data with the Bluedriver.

The Pids of interest are (on a fully warmed engine; with a good 3-5 minute test drive with a few high Wide Open Throttles while driving). Data collected must be under load. At the end of the drive put it in park and snap the throttle 3 times in a row on a 1 and 2 and 3 count.

Collect:

RPM
Baro
MAP
MAF
Long Term Fuel Trim Banks 1 and 2
Short Term Fuel Trim Banks 1 and 2
Calc. Load or ABS Load.
Voltages for all 4 Oxygen Sensors.

Bluedriver will let you share your recorded data via email.

PM me, and I'll give you an email to send it to.

With those PIDS and MS Excel we can determine if you're dealing with an AIR or a Fuel Issue. Also see the Oxygen Storage Capacity of these new Kitty Cats!!!

I will post test results here for everyone to see!!!

I changed oil and did KAM reset this weekend. Still seeing the same readings for fuel trim and o2 voltage. Misfire counts have increased. Symptoms are more noticeable as well - intermittently shudders when parked or idle, engine revs higher when accelerating… I’m attaching a copy of mode 6 report in case anyone wants to take a look. You can see where one of the misfire tests failed. But it passed once I ran the report later on in the day.

When you say the engine loses power and revs high when accelerating, is the transmission slipping?

I don’t necessarily feel anything “slip” it’s just noticeably different and progressively getting worse… I did record some live data as was suggested in one of the comments above. And also after revving the engine while in park I noticed a smell that was almost like a sweet smell coming from the a/c. Couldn’t tell if it was coolant or gas though…

The Air Ratio is the Actual MAF reading divided by the RPM. We know that the air an engine inhales is proportional to its RPM. This ratio line should be perfectly straight across the entire RPM range of the engine. In the case of this Ford, it is.

Below is an example of a dirty MAF, It Over-reported at low RPM and Under-reported at high RPM. Notice the curve trend.


So far we know the Air was read properly by the MAF from this one graph, but in the graph below this engine has fuel trim at all RPM ranges. If the air was measured correctly, this would leave the problem on the fuel side! We can see the trims are very negative before that throttle plate opens up, but remain negative throughout the entire Rpm range. What can cause this? Leaky Injectors, Fuel Pressure too High, Open Purge Valve with a saturated canister? In further graphs we will see Bank to Bank trims near identical, this would rule out leaky injectors, although possible, they would have to be leaking perfectly balanced between both banks to go unnoticed with this data set. A faulty purge valve would have provided better trims at higher rpm, with or without a saturated canister. These trims are linear, Fuel Pressure becomes the number one suspect. Also in this graph, we can see the PCM still has fuel control.


It should be mentioned that the data in the above graphs has been manipulated by MS Excel to display all the recorded data based on Engine RPM from Low to High. Products like the E-Scan Elite will have you to take a test drive from ZERO to WOT. With this method, you can just drive around and safely get the engine through its paces.


The above graph further solidifies the Air measurement was correct. What the engine can theoretically ingest matches what the MAF is reporting. This Theoretical airflow is calculated from engine rpm and size and multiplied by the Absolute Load (which is the Volumetric Efficiency). I have yet to use complicated airflow calculators that take into account Barometric Pressure and Temperatures; that's not to say they will never be required!
These Oxygen sensor graphs show the sensors are telling the truth. We can see some nice fuel cuts, and near the end of this test drive a few snaps and we can see a couple of short high oxygen storage capacity from the Catalysts. These Cats are in danger of raw fuelling, which makes Oxygen Storage Capacity testing not a good idea until the fuelling issue is addressed.


Sorry took so long!

Thank you for reformatting your post!
Impressive as always Paul. The second MAF example is probably the clearest representation of a misreporting MAF I have seen with scan data.

Thank-you Noah. I should have attached the graph with the Fuel Trims that went with the "Dirty MAF"


Seeing the trims puts the nail in the coffin here...


This "Air Ratio" is absolutely not my idea, I have to credit Mr. Justin Miller, he can be found on Youtube.

This is his video where I learned this method:


What I did was read Bernie Thompson's Patent for the E-scan and figured, I'm gonna try this myself with MS Excel. So once I found Justin's method, adding in Bernie's Total Fuel Trim was a piece of cake!

This makes it pretty cut and dry whether the problem is air side or fuel side.

Not only are we limited to a MAF engine to calculate Theoretical Airflow, but we can also do it on a speed density system as well!