SV reX
MegaDork
10/15/23 11:07 a.m.
2013 F150 EB
Shop did a lot of work, and part of that work was replacing the catalytic converters.
Apparently they used cats that were not OEM. Problem is its throwing a CEL now. Of course, they used them because they were less expensive. I'm pretty sure they were not intentionally trying to bypass emissions- they thought it would work.
Is there any way to get the truck and the cats to play well together?
Does the ECM tune the engine based on the readings from the cats?
I might have to switch them back to OEM cats, but I figured I'd check in the the hive first.
Following with curiosity.
Did the "bubba pipes" that came with this truck have no cats at all?
In reply to SV reX :
Yes, the engine runs based on the rear O2 sensor. Very subtle, but when it's not working well, it's easy to mess up the emissions. And oddly enough, some people make it run really odd when the catalyst is noting as failed. But I don't think your f150 did that- that was done by a friend of mine.
One thing to add, this is just the front catalyst- the rear one isn't monitored, and pretty much anything with PM on it will work.
SV reX
MegaDork
10/15/23 12:01 p.m.
OHSCrifle said:
Following with curiosity.
Did the "bubba pipes" that came with this truck have no cats at all?
Different truck. That one is a 5.0L, but it always had its cats
SV reX
MegaDork
10/15/23 12:03 p.m.
In reply to alfadriver :
Trying to follow...
You said the truck runs on the rear catalysts, and also said the rear cat isn't monitored. Was that a typo?
In reply to SV reX :
Runs based on the rear sensor, which is between the first and second brick. So it's the first catalyst brick that is the issue.
PM is precious metal. Pt, Pd, and Rh are used.
SV reX
MegaDork
10/15/23 12:17 p.m.
In reply to alfadriver :
Still learning...
"Brick"? Does that mean the actual catalytic converter?
So, there are 2 cats in the single exhaust stream?
In reply to SV reX :
Sorry, each catalyst structure is a brick to me- they are mostly a ceramic material that is like a brick. And, yes, there are two catalyst bricks in a modern system on each bank.
SV reX
MegaDork
10/15/23 12:35 p.m.
No problem. I was pretty sure I was following you
SV reX
MegaDork
10/15/23 1:00 p.m.
In reply to alfadriver :
Just double checked the truck, and I'm not finding what you are describing.
There are 2 cats, not 4. 1 each manifold bank of the engine. After the cats, the 2 pipes Y into a single exhaust pipe. There is no cat in that exhaust stream- just a resonator and a muffler.
Each cat has 2 O2 sensors. A pre sensor, and a 2nd one located directly IN the center of the brick- not behind it. Is that normal?
One other thing I noticed that I haven't seen before.. the resonator has 2 small holes drilled in it at each end. About 1/8" dia. Is that normal?
The O2 sensor in the middle of the Cats is between the primary and secondary converter brick. Basically both bricks in a single case.
You can see the heat signature on the case.
In reply to SV reX :
In the one can, there is a catalyst brick, the rear NB sensor, and a second catalyst brick. There are two catalysts in each of those. Which really means you have to change the whole thing.
The holes in the resonator is normal. There a lot of water that can build up in there and needs to drain out.
SV reX
MegaDork
10/15/23 1:16 p.m.
Perfect. That's the info I needed. Thank you!
You may get by with the latest reflash, which may include a loosening of the converter monitoring between what is loaded in your PCM and the latest software. But those converters look a lot smaller than stock and may not be good enough.
That's assuming that the oxygen sensors are good (not Bob's Mystery O2s from Amazon or Rock Auto) and there are no exhaust leaks upstream of the converters. Warped exhaust manifolds is apparently a thing on the 3.5 Ecoboost, have not run into it personally. I have also had quite a few aftermarket converters that required some touch-up work with the welder because the cases were not fully welded as delivered. My favorite was a manifold assembly where they missed a 90 degree arc on one of the tubes. Oops!
SV reX
MegaDork
10/15/23 1:17 p.m.
...TIL the difference between a "brick" and a "can" and a "cat"
SV reX
MegaDork
10/15/23 1:19 p.m.
In reply to Pete. (l33t FS) :
I will follow up on that
A common fix on prius exhausts with replacement cats is to put a spacer on the O2 sensor. I don't know anything other than some claiming it will eliminate the light coming on. In your case why not take it back to the shop and ask them? Did they use an EPA approved cat?
To the best of my recollection, this is the 1st post on GRM where I've seen the word "brick" used for a catalytic converter called a brick. But Alfa has forgotten more than I'll ever know about Ford emissions components so I'm happy to learn.
What's the best way to replace failed cats? Low mileage junkyard pieces?
In reply to OHSCrifle :
Sadly, the more modern the vehicle, the more likely OEM replacements are needed to keep the CEL off. OEMs bake in a lot of safety to avoid a forced emissions recall. But at the same time, the odds of a catalyst failure has gone down a lot in recent years before 150k miles.
I've always heard the internals called the "brick".
Sadly, it is federally illegal to sell a used converter. You may find a junkyard who doesn't care about no dang laws, but more likely they pull the converters to scrap for themselves.
In reply to Pete. (l33t FS) :
Didn't know that either. TIL lots of stuff.
I know in some instances you can get by with an antifouler to slow down the response rate of the "higher flowing" replacement cat. You keep triggering the cel because the rear o2 sensor rate is switching too fast. You pull it out of the main stream and the rate goes down. It's still going to read the efficiency, just a different way.
