I'm looking to delete my cats on my 5.4 an I'm just wondering what woul need to be done with the oxygen sensors. I want to run true duals with an H pipe but I'm not sure how to fool the sensors. Any ideas?

 

Some tuners allow for Oxygen delete..... check around. SCT maybe?

 

Yeah I know that but the problem is I don't hae 350 bucks for a tuner right now but I do have access to exhaust building equipment and all the pipe I could want for super cheap. So any other ideas besides the tuner?

 

Deleteing the cats won't do anything besides create a headache. You won't gain anything, these engines are designed to run with the slight back pressure from the cat. They actually run better with them on. Trust me after running enough modular 4.6's in enduro races they run much better.

 

Not sure what the deal is this week with everyone wanting to get rid of there cats , I think there are 3 on the top ten list right now. But as mentioned above you will gain absolutly nothing but a sticky pollution spewing truck.

 

The factory 3" system already flows more CFM than a stock 5.4 can produce now if you really wanted true duals for the cool factor I would probably go with dual High flow Cats and the muffler of your choice but keep in mind you wont gain anything performance wise but it will be kinda cool

 

I think you would get the same results with a single in dual out muffler for alot less cost than doing true duals with dual cats..

 

There is a ton of bad info here. MurderMode. Sorry your question didnt get answered here.

 

I was just thinking the same thing. We went from what tires will fit/my battery is dead to cat removal.

 

What bad info are you referring to??

 

Well... I have been around this stuff for a while. I posted earlier about doing this for a work truck. Not because I didn't understand about removing a cat, i just wanted to triple check that the OBD2 wouldn't pick up on a lack of catilist.

To start I see a lot of people talk about back pressure. I assure you, if you have your stock manifolds in place and a Y-pipe, you will have no lack of back pressure. Above and beyond that, most people post these things without understanding it. Im sure we all have heard "Engines need back pressure" when discussing exhaust upgrades. That phrase is in fact completely inaccurate and a wholly misguided notion.
Your exhaust system is designed to evacuate gases from the combustion chamber quickly and efficiently. Exhaust gases are not produced in a smooth stream; exhaust gases originate in pulses. A 4 cylinder motor will have 4 distinct pulses per complete engine cycle, a 6 cylinder has 6 pules and so on. The more pulses that are produced, the more continuous the exhaust flow. Back pressure can be loosely defined as the resistance to positive flow - in this case, the resistance to positive flow of the exhaust stream.
The astute exhaust designer knows that you must balance flow capacity with velocity. You want the exhaust gases to exit the chamber and speed along at the highest velocity possible - you want a FAST exhaust stream. If you have two exhaust pulses of equal volume, one in a 2" pipe and one in a 3" pipe, the pulse in the 2" pipe will be traveling considerably FASTER than the pulse in the 3" pipe. While it is true that the narrower the pipe, the higher the velocity of the exiting gases, you want make sure the pipe is wide enough so that there is as little backpressure as possible while maintaining suitable exhaust gas velocity. Back pressure in it's most extreme form can lead to reversion of the exhaust stream - that is to say the exhaust flows backwards, which is not good. The trick is to have a pipe that that is as narrow as possible while having as close to zero backpressure as possible at the RPM range you want your power band to be located at. Exhaust pipe diameters are best suited to a particular RPM range. A smaller pipe diameter will produce higher exhaust velocities at a lower RPM but create unacceptably high amounts of back pressure at high rpm.

There is so much info about this that is backed up. I couldn't fit all of my cars or past projects into my esig. The exhaust back pressure issue has been talked about so much in the Mustang world. My 05 Shelby was a perfect example. We had done an axle back on the car and we lost power. You might think SEE TOLD YA LESS BACK PRESSURE. Well, when the car went to long tubes, x pipe and straight through mufflers, guess what.... significant power gain of almost 25 HP and a whopping 33 in tq.

The other part was the pollution part. Want me to start on that?

Now I am new to this board. But I have built dozens of FEs, Small, Yblock, 385s, and mod motors. I would like to be a part of this web site and hopefully contribute.

This guy asked for help, not opinions or puking of bad info that someone read on a message board years ago and probably repeats daily.

 

I know very little about exhaust flow but I would guess the gains you saw on the mustang are from the long tubes you installed of which the OP is not doing and as far as removing the Cat and gaining power I can say from recent experience that I gained absolutly nothing in seat of the pants feel and no gain in MPG. What I did gain was my truck smelling like and an oil burning 1960,s ford falcon.

 

That's great and we encourage it.

That being the case, you could have easily posted the response in post #11 to start with instead of apologizing to the OP for his not getting his question answered and then being condescending with this type of post.

 

Posts have been edited to remove unnecessary bickering. Let's keep it civil and try to answer the OP's question and leave out all of the name calling and other unneeded junk.

 

I was thinking the same thing when I saw the title!


To the OP: you will not gain anything from doing this except a stinky, more polluting truck. Unless you have supporting mods to rid of this equipment, then I wouldn't do it. You will pollute more(I'm not a tree hugger, I just would like my 8 month old to grow up in a world where she doesn't have to wear a respirator.) and your truck would be insanely obnoxious and annoy just about everyone in the neighborhood. I'm not sure about you, but I enjoy my sleep and there is NOTHING I hate more than some idiot who thinks having the loudest exhaust in the world and revving his engine at 1 am and waking up my wife and baby. I'm not saying this is you, but its hard to keep a vehicle with no cats unheard at night. You'll attract attention from the police, which no one wants either. Put a Magnaflow or Flowmaster on it an make it sound like a good v8.