I have a 2002 supercrew with a flowmaster cat back exhaust. It doesnt have the deepness im lookin for. Does anyone know if they make a straight y pipe from the headers to the muffler that eliminates the cats. I know emmisions would be a problem but I can always put the stock cats back on before I go. Or anyone have ideas of what I can do. Thanks....

 

There are a few problems with doing that.
First the O2 sensors are in the cats. It would probably be possible to put in a chunk of pipe where the cat are and put a bung in it for a 02 sensor, but more than likey it will not run right due to inproper air/fuel metering. Also, you cant get rid of the o2 sensors or it will not run period.

Second, there will be little backpressure. With out backpressure, your going to loose torque, and kill your gas milage. These newer fuel injected engines require backpressure to function properly, unlike an old muscle car where you bolt on a pair of long hi-flow hedders and huge exaust pipes and go.

The best/most sensible thing to do would probably be replace the muffler. Maybe try a 40 series flowmaster.

Some people gut the cats, but then the backpressure issue arises again.

Good luck.

 

You can go to rpmoutlet.com and they have o2 simulators that will send the correct signals to the computer telling it that everything is ok even if you have no cats. They cost about 60 bucks for a pair. I thought about doing it myself but I get mixed messages about whether or not cutting the cats off backpressure wise if it will harm the engine. Also nobody can give me any written proff because it all sounds theoretical.

 

My cousin tried some of those 02 sims. They worked, but not that good. Killed a little of his performance. This was on an S10.

Ive also heard little back pressure will hurt the engine. I can see how it could. I know it can kill performance though. My 99 4.6 seemed to loose bottom end ever since I got dual exhaust on it with 2.5 inch pipes and glass packs. Got rid of a lot of backpressure.

 

If you can see how it would effect it please share the knowledge. Otherwise why in the world would they come out with high flow cats and shorty headers if the loss of back pressure is actually going to hurt your performance. It would be helpful if you can give it to me in detail as much as possible. It would be even better if you can show somewhere that there are some numbers tied with this like some before and after dyno #'s. Also what were you and your cousin's truck doing different. I have a 4.6 5spd and I can tell the slitest change in power and if yours is an automatic it would have to be greater than a 10 hp or torque loss for you to even notice anything outside of gas milage.

 

I really dont want to go into details right now but ask anybody here. ***** ask MIke Troyer in the chip section if you want the most detailed answer you will ever read in your life.

What do you mean what where are trucks doing different.

And what did you do to your exhaust exactley? Yes the stock one is a little restrictive so opening it up a little will help, but mine is opened up too much, and yes, it definatley made a difference.

DONT TRY TO START STUFF WITH ME

 

Don't get all touchy now. I ain't trying to start anything. Theres no need to make a threatening type of coment like that. I'm new so just ease up on me a little bit know.

What I ment was were your alls trucks for example, feel like they where bogging down during acceleration compared to before or something like that.

I have just a SI/DO flowmaster 40 on the stock y pipe. Still in college didn't want to spend an extra 100 bucks. 200 was enough.

Thanks for the information on who to talk to that will give me a straight up answer and explination I am looking for.

 

Sorry, it was kind of a bad day

The truck didnt feel like they were bogging down, just didnt have the snappyness or acceleration that they did before.

With your setup you wouldnt have lost as much backpressure as us people with the true dual setup.

 

Its all right.

I here a lot of people on this board say that they loss their low end torque. So my thought is that the stock exhaust goes into a y pipe and equilizes the pressure on both sides. And on any old pickup you add a H or X pipe it gives better low end torque. So in order to keep your low end torque with real duals and keeping the cats, would it make since to to some how incorperate a H or X pipe after the cats. I could be wrong on this but logicly it kind of makes since to me unless Mike Troyer gives me details that blow this idea out of the water.

 

Yeah adding a H or X pipe to a true dual setup helps a lot usually.

Ive been wanting to put a X pipe on my exhaust for a while now to help it out some.

 

ive seen a couple companies that make a no cat x pipe for our trucks but i think most people use them on lightnings. but you could use one of those and then run pipes wherever you want them.