I have a 2006 F-150 5.4 V8. I haven't done anything to my exhaust yet, but I'm going to before long. I'm thinking magnapacks maybe flowmaster super 44s, not sure yet. I'm also thinking about high flow cats. My question is: Where should my O2 sensor go if I do get high flow cats? I have 1 O2 sensor on the engine side of my stock cat and the other O2 sensor is mounted in the middle of the stock cat.

 

I'm thinking about going with the magnaflow 94106 high flow cats

 

As close to the factory location as possible. Mine are in the cats themselves and I haven't had issues knock on wood. Usually an inch or so behind the new cats, but to be honest, you could get a code, you might not. It's just the best way to prevent it.

 

Magnapacks not flowmaster. O2 goes directly behind the cat.

 

Behind meaning downstream of the cat?

 

Can an exhaust shop mount the O2 sensor in the body of a new cat? Or do the high flow cats have a spot to put the sensor already?

 

The 94106s don't have a place for the o2 sensors. Just have a shop mount them right after the cats and you'll be fine.

 

^ exactly.

 

I bought the cats with the O2 bung in them already, no problems and running over two years.

 

What cats did you get that already had the bung?

 

Its probably the Magnaflow #94136 cats, same body, just an O2 bung at the end of the body.

Batn68, been listening to your Youtubes lately, you need more vids!

So you have never had CEL issues with the #94136s? I have always recommended the #94106 over the #94136 cats due to a few reports of CELs after install of the #94136s. Could be dirty O2s re-installed but that is what I was reported a couple times. The sensor re-mount after cat is almost bullet proof guaranteed until people need new down streams. Were you already custom tuned to have them off?

 

Yes they sure can... they did that with mine... I have 94106's.