So I bought this truck yesterday it's a 02 with the 5.4 and it had a bank 2 senor 2 code. Didn't think to much about it until I got underneath it today. Bank 2 has had the cat deleted but I still have the bank one cats. Is the uneven back pressure going to lead to more issues? Thanks in advance.

 

Yea....of course.

02 sensors and all?

 

All the sensors are there, looks like they cut out the drivers side cat and welded a pipe in and left the passager side stock. This is just a beater farm truck so I might just delete the other side.

 

So it has 3 cats? or 1?

My truck runs well on two, one on each bank. But my original ones were shot so I replaced with Magnaflow and paid a local shop to do the welding professionally.

Running it with no cats is miserable. Its like trying to ride a horse than has been shot in the leg.

 

So true, you need at least one cat per side.

Running two cats on one side and one on other can be just fine AFA parameter margins. ALA there are no DTC's (420/430). You can get away with running just the smaller upstream cats (which are more restrictive than the larger dowstream) if the connections are tight. However, and since he has a DTC (the code isn't mentioned), most likley a PO430, his upstream cat either isn't in good shape or the connections are leaking.

 

What's funny Jbrew is some people don't agree. There is a friend of a friend here in my local area who I asked to weld the cats on for me. He is known as one of the better mechanics in my area. He asked why I was putting cats on it and why I didn't leave it be and I told him it drove like crap. It was sluggish. Anyone who's driven a 10th gen enough should know the difference immediately.

To this day, he completely disagrees. He doesn't think that back pressure is a real thing and he doesn't think that truck runs any more sluggish. He has a 99 Expedition 5.4 with the cats off and swears it's the same.

 

It's not so much back pressure as it is the air to fuel calculations. You've got a lot of data coming from sensors that goes into those fuel tables.... I was just reading earlier today that even the ACT plays with things like EPC pressures. The high flow cats work great for these motors.... you just need a proper reading at the second O2's in order for the whole system to work as intended.

You could get away with pulling cats off the old EEC-IV stuff all day because it wasn't using that data like the OBD-II system.

 

2 cats, both on passenger side. Codes are p0156 and p0161. All this being said it seems to run really well.