’09 with 5.4, 180k miles. (Please note: I work from home, and don’t drive the truck very often nowadays. Maybe a short (< 30 miles trip) once or twice a week if that.)

12/31/22 while on a little get-away weekend the CEL came on. We just happened upon an auto parts shop, so I stopped in and asked them to check codes. “O2 sensor” code (don’t recall the actual code number, but if I recall it said “Bank 1”).

Thought to myself, “Ok, take care of this next week.” Kept on driving down the road, finishing up our trip and returned home.

Truck was and has been driving fine.

Started up the truck a couple of days later: CEL gone. And had remained out until now (1/16/23).

Went to the local O’Reilly’s to have them check codes: P0420 and P0430.

Let me add, the truck has been, for a while now, a strange unpleasant pungent exhaust odor. Not a burning smell (like oil) or like excess fuel, but not a (for lack of a better descriptor) “pleasant” odor. (I had posted about this smell earlier on this forum. I just hadn't gotten off my butt and done anything about it. Won't be able to avoid it now...)

So, wondering if this all ties together: O2 code, exhaust smell, and simultaneous P0420 & P0430 codes? But also, to me, what’s odd is having both cat codes fire off at once.

Any thoughts, suggestions?
Thanks all

 

Cats are shot both sides.

 

... probably ... and the reason for their failure is still unknown.

 

Isn't it kinda of odd they would both go at the same time?
And yes, what would "fry" them: rich condition, exhaust leak upstream, ...????

Any way I can check to see if they're shot, or does that take special tools?

I'll start Googling too, just thought I would ask.

 

A muffler shop can test the cats for excessive backpressure.

 

That's not a consideration when dealing with efficiency codes.

 

It can be. The odor tells me they may be getting plugged up. Infrared thermometer may help with diagnosis.

 

The odor and the DTCs indicate that the converters ain't convertin'. IOW, "dead cats.."

No evidence of any restriction of exhaust flow.

Of course, the REASON for their failure needs to be found, usually due to a rich mixture or contamination.

 

Rather than me probably misdiagnosing the issue, I took the truck to a trusted shop we've used in the past, have them hook up their analyzer and see what they could find.

They reported all the fuel trim readings, etc. were within spec. He suspects bad cats.

 

Cats are consumable items. 180k isn't far off. Depending on driving habits, oil change intervals, fuel quality, etc.

I just did a set on a 2009 Ford Explorer a few weeks ago and it has 230k on the clock.

However, according to my scan tool, the CEL was lit for the cat codes since 18k miles, so they really went bad at ~210k miles. Pretty much went a whole year before replacing them (due to emissions inspection).

I replaced them with Walker cats and new Motorcraft sensors. I also had to replace the entire cat back exhaust as it was rotten.

I do recommend getting the old cats and bringing them to the recycler so you can get some of your money back.

 

Looks like I need to replace my cats ('09 with 182k on it).

I plan on replacing the truck with a family members truck that will be available soon, so that will enter into the decision.

Anyway, I've read some reports where they've stated you need to use the OEM cats or the CEL would/might come on.

Any truth in that: you have to replace with OEM? Or can I use just any brand cat?

 

Any brand OE design should be fine, I recommend Walker.

https://www.rockauto.com/en/catalog/...converter,5808

 

"I do recommend getting the old cats and bringing them to the recycler so you can get some of your money back."

Yes sir, agreed. I had already listed that as one of the steps.

glc, thanks for the hyperlink