Hello all,

I have a 2014 Ford F150 5.0 with 59,5xx miles. About a month ago I was driving a short distance and noticed a slight rattle like sound. After I ran my errand and got back in, no noise. Then the CEL came on, P0430. Cleared it and it came back shortly after. Noticed after that the rattle noise was returning at higher 4k+ RPMs. I took it out to a back road and opened up the throttle. CEL started to flash around 5k RPMs. Let off the throttle and CEL stopped flashing. Repeated with same results. Researched the code. Crawled under and hit my cat with hammer heard some rattling. At this point I had the P0430 code and a pending code for a misfire on cylinder 8.
Decided to replace both CATs (was not aware of the warranty on them). Replaced both with Magnaflow OEM direct fit cats. Part number 52138 and 52139. Had to fight to get the passenger downstream O2 sensor off, ended up damaging it in the process. So we moved the driver side O2 to the passenger side and put a new one on the driver side.
Instantly had better performance. No rattle noise, no flashing CEL when opening the throttle, and overall seemed better. Drove it for a bit after clearing the code and it came back. Cleared it again and it came back.

Took it to Ford for diagnostic since it could be a slew of other issues. They stated the computer needed to "relearn" the readings. No misfires, no fuel leaks, etc. Just aftermarket CATs and the computer doesn't like them. Makes sense to me I guess. No issues while the tech was out riding around. They reset the computer and cleared the codes. Drove it around today, and the code came back. Now I'm seeing P0430, and P0420 is pending. Called Magnaflow and they recommend unhooking the battery for 15 minutes to let the computer reset. Elsewise to send them a picture of the code and receipt and they'll start a warranty process since according to them the OEM ones should look and act just like factory ones. Computer shouldn't be throwing a code at all.

Anyone had a similar experience? Or thoughts on what else I could do? I'm contemplating replacing the upstream O2, but that doesn't help if P0420 is creeping up.

 

As you know both codes are CAT efficiency.
A proper diagnosis in in order and not just swapping parts.
May be the new Cats, maybe not.
The rear Ox sensors monitor Oxygen storage in the Cats and compare to the upstream >switching actions< as the way they access the Cats functions.
Diagnostics involves using a Scanner to look at the front sensor switching and the rear or downstream Sensor actions.
What should be seen is the downstream action should be quite stable and not change very much as compared to the upstream sensor on the same bank, after full warmup.
If the downstream moves in value and tends to follow the upstream, the Cat function is poor and generates the code for that bank.
.
Now the questions are,
Are the CATS not performing?
Are the Sensors at fault.
Is the harness to both damaged or burnt?
Or a combination of faults.
Was there misfires after the Cats were replaced that took them out again?
Powering down the PCM is only needed for a minute or two at the most, to clear memory.
On the next start cycle, the PCM will run through a series of self-tests that will take some drive time to complete and begin to rebuild some tables as you drive and learn cold and hot restart functions etc.
If the Cats don't pass, that monitor will not complete and a code P1000 will be set along with the codes 420 and/ or 430. All monitors must pass testing before code 1000 will clear.
The faults will be detected again because rebooting never >fixes< any fault.
You see why Diagnostics has to be done first to solve the issues and not expect to just change parts.
Doing his has already cause confusion with no good end results.
Good luck.

 

I actually think very few people have had to replace their cats at this point. I'd continue the process with magnaflow at the moment and see where it leads you.

 

It's interesting Magnaflow would want to replace their cats so soon and Bluegrass's testing first procedure sure seams like the way to prevent a reoccurring problem.
Best of luck

 

Maybe this

will help you

 

You have a KNOWN misfire on #8. Remember that FLASHING check engine light and pending code? The flashing light indicates that a catalyst-damaging misfire was occurring at that time. Undoubtedly you've been experiencing a lower grade misfire over a longer period of time which is also detrimental to the converters, it just takes longer to ruin them. There's no surprise that your B2 converter has suffered and was ruined twice now.

If you fail to resolve the base engine problem, any replacement converter is doomed to the same outcome.

 

Thanks for the info. I've ruled out some of the issues. The only issue I cannot be certain on is exhaust leaks. I did buy this pickup used with about 42xxx on the clock. I have no idea what the previous owners did or did not do to it.

Misfire code only came up after I had opened the throttle and got a flashing CEL. There has been no misfire codes since nor a flashing CEL the numerous times I've opened the throttle after replacing the cats. Plugs and boots were replaced prior to the cats going in. I've got less than 100 miles with the new cats on. I highly doubt the new one is ruined. I've ruled out wiring issues, fuel pressure, and misfires. I believe the issue is an exhaust leak. I've got a shop lined up to check since I don't have the time nor ability to do so at the moment. Their first gut instinct was wrong cats installed (non CA emissions on a CA emissions vehicle) and their second was exhaust leak.

I was hoping for a similar experience where O2 sensors were replaced or something easily missed was the issue. Doesn't appear to be the case.

 

An exhaust leak was found at the manifold. They got that taken care of and cleared the code. Engine is sound. No misfires, fuel pressure is good, etc. They claim to have cycled it three times and it did not come back for them. They are saying it's my CAI, it's sucking too much air. I've had the CAI on for almost two years now with no obvious problems. I installed that shorty after I purchased my pickup. Has anyone seen a problem like that? Could that have caused my CAT to go bad in the first place?
I just got done driving it for about 30 minutes and the light is back on.

 

The engine sucks in as much air as it needs, you can't 'get too much air' in there unless you're using a super charger or turbo. Nothing a "CAI" does/allows will cause any change in how much air the engine sucks in.

 

Unless the CAI is messing up your MAF signal, the ECU will account for any and all air coming into the engine.