Taurus Car Club of America : Ford Taurus Forum banner

P0420 & P0430 on the Taurus

7K views 12 replies 5 participants last post by  XLR8 
#1 ·
This isn't the first time I've been around the block with this issue, as you can see in my last thread here.

This time around, my 2013 Taurus 3.5 SEL came up with a CEL for P0420 and P0430. I know this is a generic code which can mean many things, up to and including failed catalytic converters. I wanted to replace the primary O2 sensors as one of them showed no data. This was....a month ago?

Fast forward to today and I get the oil changed at my local Ford dealership per usual where I bought my car from. They end up doing a diag on the CEL and the service tech there says that it is indeed the catalytic converters that have failed. With my previous experience with the P0430 CEL in the past, the solution then was to replace the catalytic converters. This was back in 2018 and 50k miles ago. The mileage on the car was 100k and now it's 150k, or 50k since the catalytic converters were both replaced in 2018. This is where I have my questions:

  1. Why is this happening so frequently? Shouldn't CATs last at least 100k (more realistically, the life of the vehicle)?
  2. Why has the price in the last 3yrs jumped $550+? When I bought them last time in 2018, each catalytic converter was $265. Now, they're going for at least $725! The dealer quoted me $1,059 and $1,016 for left and right, respectively.
  3. Besides failed catalytic converters, what are more likely reasons for this?
  4. After performing the repairs, what is action I can take to prevent this from happening again?
Font Rectangle Number Paper Paper product
 
See less See more
1
#3 ·
He was saying that that's the price he bought them for himself.. also check RockAuto they have them for way less.

As for the technical question the usual culprit is O2 sensors. Running rich is usually what messes them up, as Q already pointed out. No other issues with the motor?
 
#4 ·
Update time:

Replacing the primary and secondary o2 sensors appears to have resolved the problem. I replaced them over the weekend and the car has not given me a CEL of any kind since. I also replaced all 6 spark plugs as they were due for service as well, 75k miles.

Results from Torque:

Light Gadget Font Electronic device Screenshot


Everything seems to be working good on first start after everything was done.

Asphalt Rectangle Organism Slope Font


This is me driving around. The hills and valleys are shift points.

Product Rectangle Slope Font Line


And the car coming to a stop.

Rectangle Slope Font Asphalt Parallel


Slowing down, accelerating, then slowing down again.

Joint Slope Rectangle Font Plot




Yes, I replaced the catalytic converters myself last time. I bought them from one of my local Ford dealerships and did the work myself.

Buying CATs from RockAuto, that's the first place I go to for all my vehicles' mechanical needs. I'm in California. The problem there is that the CATs that RockAuto has available are all EPA certified, and me being in California means that they need to be CARB certified, not EPA certified. That said, I cannot buy CATs for my Taurus from RockAuto, they have to be from Ford.

The lesson I learned about this is to replace the o2 sensors first if this P0420 and / or P0430 CEL happens again. Particularly if the CEL turns off and on as it was doing this time. The time I replaced the CATs (as referenced in my OP), the CEL was always on.

And no, there's no other issues with the motor.
 
#5 ·
After almost two weeks of being free of P0420 and P0430, it has returned.

I guess this means that I do indeed need to get new CATs for my Taurus? Any other suggestions before I break down and spend $2,000 on catalytic converters?

Light Font Screenshot Multimedia Software
 
#8 · (Edited)
After almost two weeks of being free of P0420 and P0430, it has returned.

I guess this means that I do indeed need to get new CATs for my Taurus? Any other suggestions before I break down and spend $2,000 on catalytic converters?

View attachment 219650
When you clear your DTCs, problems can still exist in the car, but the CEL won't come back on until you complete a drive cycle. Sometimes this can take several days and/or many miles if you don't know the exact criteria for the cycle. Once the drive cycle is completed, and if problems still exist, codes will be thrown again and the CEL will come back on. Many people think that CEL off = no problem, but this is only true when the drive cycle is complete. In most scan tools you can monitor when drive cycle is complete (various system monitors ready).

Perform a temperature differential check on the cats using a cheap infraed laser thermometer. If the temperature at the cat inlet is significantly higher that at the outlet (200 degrees or more) then your cat is clogged up.

Before replacing your cats again, monitor commanded AFR vs. actual AFR. As someone above correctly pointed out, if the car is running rich it will drastically shorten the life of your cats.

Also, I would first try cleaning the cats. People scoff at this, but it does work (around 60% of the time). You can clean the cats by removing the O2 sensors and spraying SeaFoam into the bungs. Spray a lot, at all different angles, to soak the insides of the cats to the greatest extent possible. Replace the O2 sensors and let the car sit for 2-3 hours before starting it. When you do start it, be prepared for it to smoke like Cheech & Chong through the exhaust for 20-30 minutes as the SeaFoam burns off. Then, without clearing DTCs, complete a drive cycle and see if the CEL turns off on its own.

If you do end up having to replace your cats, I would check CarID for pricing (once the page loads hit CTRL+F and search for "interceptor"). I've been very pleased with CarID's prices on many things (including cats for 2 different cars), as well as their fast shipping and excellent customer service.
 
#10 ·
Sorry guys, I'm not on here much.



How do I go about doing this?

Log commanded vs. actual AFR.
Please explain further. I'm not familiar with either of these. Is this something I can do from Torque?

When you clear your DTCs, problems can still exist in the car, but the CEL won't come back on until you complete a drive cycle. Sometimes this can take several days and/or many miles if you don't know the exact criteria for the cycle. Once the drive cycle is completed, and if problems still exist, codes will be thrown again and the CEL will come back on. Many people think that CEL off = no problem, but this is only true when the drive cycle is complete. In most scan tools you can monitor when drive cycle is complete (various system monitors ready).
That's what I showed in my last post. The drive cycles had been completed and shown as complete per Torque Pro app as shown in my post where it had been resolved.

Perform a temperature differential check on the cats using a cheap infraed laser thermometer. If the temperature at the cat inlet is significantly higher that at the outlet (200 degrees or more) then your cat is clogged up.
I have one of those. I can do this.

Before replacing your cats again, monitor commanded AFR vs. actual AFR. As someone above correctly pointed out, if the car is running rich it will drastically shorten the life of your cats.
Again, I'm not sure what commanded AFR and actual AFR is, so I'll need clarification on this before I can test / check for this.

Also, I would first try cleaning the cats. People scoff at this, but it does work (around 60% of the time). You can clean the cats by removing the O2 sensors and spraying SeaFoam into the bungs. Spray a lot, at all different angles, to soak the insides of the cats to the greatest extent possible. Replace the O2 sensors and let the car sit for 2-3 hours before starting it. When you do start it, be prepared for it to smoke like Cheech & Chong through the exhaust for 20-30 minutes as the SeaFoam burns off. Then, without clearing DTCs, complete a drive cycle and see if the CEL turns off on its own.
Spraying SeaFoam into the primary bungs won't be an issue. However:
  1. Is there any way to easily get to the firewall side primary o2 sensor without removing the upper intake manifold?
  2. After dousing the CATs in SeaFoam, do I need to reinstall the o2 sensors and button everything back up before starting the car again? Or do I need to start the car with the primary o2 sensors removed?

If you do end up having to replace your cats, I would check CarID for pricing (once the page loads hit CTRL+F and search for "interceptor"). I've been very pleased with CarID's prices on many things (including cats for 2 different cars), as well as their fast shipping and excellent customer service.
I'll check with CarID. But if they only sell EPA certified CATs, I cannot purchase them from CarID as that would make them illegal to use in the "wonderful" state of California where I reside. The CATs I purchase must be CARB certified. I ran across this when I was looking at RockAuto for pricing on replacement CATs.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top