2007 f-250 codes - Ford Forums

Boscat · 08-02-2009, 21:39

I purchased a truck about 14 hours from me so I flew there to pick it up. The guy did tell me that it needed a fuel pump before I could take it so we replaced that, and looking at the in tank filters it was a good idea. I took my scanner along as there was also a light on in the dash, and it came up as po171 and po174 which is lean on both banks. I thought that was do to the fuel pump not being able to deliver the fuel it was suppose to. Cleared the codes and truck ran like a top. I make it about a 100 miles towards home and the light comes back on. This time code po420 shows, bank 2 cat below threshold. No problems with running, so cleared the code and went again. 50 miles later lights on again. po420 and po430 which means both sides the Cats are not doing their job. Thats where I am right now. What are the chances of both Cats failing at the same time? It does have about a 100 000 miles on the truck and it has magna flow dual ex but only from the cats back so I dont think that should be effecting the O2 sen or the performance of the Cats. I guess that is my question, would that effect performance of either one or are both Cats really gone.

**360ci** · 08-06-2009, 13:53

Bad cats can mean less performance. If you had the truck for the last two years you'd be able to notice if there was a power loss. For now, I'd replace the O2 sensors and go from there. $100-150 for some O2 sensors is a lot cheaper than replacing the cats, and O2 sensors are a regular maintenance item anyway (60-80K). If the sensors are original, then you lucked out with them lasting 100K (or at least the previous owner did), and it can also mean the truck wasn't too abused with the engine running in the mid to high rpm range creating more work for the O2 sensors. Anyway, that's where I would start.