Ok, I understand. Why would they not be getting hot enough on my truck but they do on other trucks with similar setup? When I decided to install the cats I read up on it beforehand to be sure it wouldn't cause problems and I received good input from others. What's the missing link?

 

I dont know why it works on some and not others. But if you are getting a hesitation I would have that checked out. To me the exhaust gases are hot enough. But I had someone call me with this same issue on another vehicle. He removed the pre-cats and the exhaust temps werent there. Those front cats help heat up the exhaust before it gets sent down stream

 

Ok, since the hesitation and shutter wasn't there before the cats swap I'm assuming the cats caused my problems, but I have been to a mechanic several times and he's helping me diagnose the problem. He says the cats didn't cause the problem even though the timing seems that they did. I guess the trucks can't survive on a single mod...you start one you gotta follow it with another.
Thanks for you help MagnaflowRep! If you come across any more info that might help please keep me posted.

 

No Problem thats what Im here for

 

Magnaflow Rep if I may ask a question. For my truck, do I need to get all 4 Magnaflow cats? Cant get just the rears? I'm going to be doing 2.5" true duals with mufflers and I wanted to get rid of the 4 cat setup for the Magnaflow rear cats for these trucks. And is there a specific part # thats great for these trucks? I was going to get the 2.5" part # 94006s. Thanks

 

I left work yesterday and my truck ran horrible. It feels like all of a sudden the engine loses power and is getting no fuel or air. I drove to my mechanic shop and he started looking again spraying all over the hoses and such looking for an air leak. Nothing appeared so he took the air intake apart and as he would move the air box or tube around the truck was cutting up like a mother. So he took it all apart all the way to the throttle body and checked every wire and all over for holes, cracks. The conclusion from this is to take the new MAF sensor back and get another one. Maybe the one I got the other day is bad. I'll let yall know tonight when it's on if this was the problem. This has us all confused.

 

well this is all no good. I was going to have my 4 swapped out this week. Now Im wondering if I should just do the rear two but Im not sure if it will be much louder that way...

 

I replaced the 4 stockers with only 2 rear Magnaflow Cats. This is what most people do. I hope you have better luck than me. It is definitely louder with 2 Magnaflow high flows. What type of exhaust do you have right now?

 

Yeah thats exactly what I wanna do. Now after hearing about the purpose of the front cats Im questioning again. WhatI dont understand is how do the 06+ have no pre-cats & just the regular 2 cats with no problems then? I dont want them front cats cause of all the silencing they do.

 

The pre cats are there to reduce the"Load" on the two larger ones, Ford did this to incease the lifespan of the converters, and with the new technology and the lowered price of converters, they don't need all four anymore. I have never heard of anyones EGT's being too low for converter too work, the O2 is the only thing that needs to be up to temp in a exhaust system, and it has it's own heater.

 

Thanks for the knowledgeable info Joshmac4.6 That's one less thing for me to worry about being the cause of my problem. I've got an exhaust leak about 8" behind the passenger side cat. I'm going to get it fixed today. Who knows, maybe it's causing some air control problems...if not it'll sound better anyways. Do you think I should replace bank 2 sensor 1(the other front 02 sensor) since I replaced bank 1 sensor 1? The old sensor had BOSCH and Ford on it so I assume it's the one from factory. Prob a little old.
BTW-Are you going to put high flows on yours?

 

I would go ahead and replace B1S1, it could help it out. But no I won't be running high flows, this exhaust will be on until the turbo setup, then I will run a single high flow. I will be chopping off the two big cats on mine though, hoping to sound like a older mustang gt, but not holding my breath.

 

I already replaced bank 1 sensor 1 because the code said it was slow response. Check engine light is back on so I'm going to get another diagnostic and probably replace bank 2 sensor 1. What do you think?

 

My bad I meant B2S1

 

Wow, I'm even more confused now. I stopped at Advanced to get the other MAF sensor and check engine light was on so i got another DT. Guess what...
P0133
02 Sensor
Slow Response
(Bank 1 Sensor 1)
again........damn I just replaced that 02 sensor. Man I'm confused...I guess I'll just cut everything out from under it and give it hell to release my anger and frustration. If there's a magic word out there please somebody say it. I really do appreciate the help and advice thus far but I've got to get this $300 modification fixed.
anybody got some dynamite.