Well, as the title states I’m a former BMW owner looking to replace my cats - 2006 Lariat. I read in the sticky that the most common aftermarket for our trucks is the 94106 from magnaflow.

As a BMW owner, we know that aftermarket’s don’t necessarily play nice with our cars. Some people get lucky, many don’t.

Any reports of issues with the magnaflows or is it pretty much guaranteed to function as it would if it were OEM.

Or is it better to go with direct fit aftermarket? OEM too expensive to even consider

 

Nothing is absolutely guaranteed to function as OEM, but it will run fine. They *might* cause a CEL with a low efficiency code, that can usually be taken care of with a spark plug anti-fouler between the bung and rear O2 sensor.

 

Like glc said, nothing guaranteed, unless OEM.

I've done lots of cat jobs lately due to stolen or otherwise aging cats (people are keeping their cars longer) and I've found that Walker brand (either 50 or non 50 state) cats work the best, 9 times out of 10 without needing an anti-fouler.

BEFORE replacing parts, make absolutely sure it really needs cats. I generally inspect the O2 sensor wiring, voltages (using a computer), and then replace the O2 sensors if something is questionable. If all passes and I get the appropriate O2 codes, I then move on to wrenching and replacing the cats. Also don't forget the gasket kit.

 

So been out of commission for a minute and I’m back. Picking up on this discussion, do you have a walker part number?

Also, I’m confused because the parts diagram at Tasca parts shows an assembly with a precat rather than a single cat. Does the 2006 5.4 come with precats or not.

It needs at least one cat. Your ears will tell you when you first start it up cold…

 

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

Looks like there are precats only with California emissions.

 

just had a peek under the truck and I see only one cat on either side. They look OEM to me. I’ll do some more searching on the walker website and make a purchase soon.

 

There are multiple part numbers depending on spec:

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

I was recommending Walker brand, because I have had the best luck with them on multiple makes and models of vehicles.

 

You posted the same link I did. That has all converters of all brands that Rock Auto carries. There are Walkers for both 2wd and 4wd, both EPA and CARB (California).

WALKER 50553 E.P.A. Compliant Info
Right; 4WD

WALKER 53569 E.P.A. Compliant Info
Left; 4WD

WALKER 53651 E.P.A. Compliant Info
Left; RWD

WALKER 50543 E.P.A. Compliant Info
Right; RWD

 

Sorry, what happened was I had the post written up and I had to go take care of the wood stove, when I got back I hit post... in that time you did what I did and posted what was on Rock Auto... lol