After I installing the Y-pipe I also had the shop take out my pre-muffler. I think I lost a lot of back pressure. Should I put it back on??

 

you mean the resonator? That should not really affect anything drastically.

 

Probably thats what it is?? It seems like ilost a lot of low end. Maybe it's the y-pipe

 

I’m confused…

Y-pipe--> Cat --> B-Pipe --> Muffler

Which one did they take out? What did they replace it with?

The Y-pipe has built-in pre-CAT. Is that what they said they removed? If so, that’s normal. That SHOULD be taken out, and you shouldn’t feel any loss of low-end at all.

Do you hear an exhaust leak?

Also, check your o2 sensors and reset your ECU. (unplug your battery for a few hours) Sounds like something isn’t quite right with the install.

 

I had cattman Y installed, had the resonator removed, and put new muffler. I think I gained power after 4 grand and lost power under 4g.??

 

I dont hear any leaks, I duno??

 

Actually you right, but it actually goes like this:

Ypipe--> Cat --> Resonator --> Bpipe --> Muffler.

Now you right either way cause most people consider the resonator part of the bpipe cause it is in one piece. But for terminology sake, it is different.

Dixit

 

For some reason I think when I had it stock it was much quicker..Spend $450 on the y and it did not do $hit. I crack my self up !!!

 

I’m guessing you got a crappy muffler.
The 5th-Gen muffler was designed to optimize flow for low-end and high-end with some sort of flap. Gains from changing the muffler have been minimal at best. (1-2 HP). I wouldn’t be surprised if you just took a step down with that muffler. It sounds like you’ve lost low-end, and trust me that’s not from the Y-pipe. I recommend keeping the Y-Pipe but putting the OEM muffler back on and see if that improves things.

BTW, what brand of muffler did you install?

 

OBX muffler

 

The y pipe removes the precats.

 

It is difficult to gauge the merit of 1 or 2 mods on the entire intake/exhaust route. Many claim the value of these parts are not really manifested well individually, but rather, as a team. If you were to install a hi-flow intake, y-pipe, hi-flow cat, and cat-back system, you would, perhaps, fully enjoy the resulting synergistic character of the team: 1 + 1 + 1 + 1 = 5, if you know what I mean...

 

On this subject, the 2k2 has a precat just after each manifold. If a y-pipe eliminated these, what would the effect be on back pressure...and would it be too much flow?

(btw, I realize ara662's car is an 01')

 

I am certain that removal of the cats would reduce back pressure but I do not know how this would impact the 3.5 from a performance stand point. Some back pressure is usually considered good to help low end torque whereas too much back pressure can sap high end horsepower.