Changing the cat definitely improved some of your flow if your old one was rattling. It probably changed the sound, too.

If you go to an aftermarket muffler, you'll really enjoy the meaty sound you get. If you're worried about it being too loud, check out a Flowmaster Delta 40, which is supposed to sound like a Super 40 but reduce interior droning. Personally I liked the Magnaflow I was using on the stock exhaust setup, and though it seemed a bit loud at first I quickly got used to it.

If you want a resonator to replace your stock unit, check out the Magnaflow 4" round muffler/resonator. You can get them in a few different lengths, and I think they sound great. I'm using one in conjunction with a glasspack on my current setup, and it really rounds the sound out nicely. A great vendor for Magnaflow stuff is www.justmagnaflow.com.

Keep the resoator. There isn't a performance gain to be had until you REALLY start flowing. My 93 didn't come from the factory with one, and I added one. It made a remarkable improvement in the quality of the sound.

Having changed out the muffler to a Magnaflow (and remember, I'm not supercharged, so my factory muffler was single-out), there'* two things I'd want to know if I could go back in time before I changed it out. They are:
(1) It won't make much of a difference.
(2) It makes a hell of a difference.

I think with #1, we're being realistic. Just the muffler swap isn't going to carve seconds off your quarter mile times. If you expect it to, you're going to be disappointed.

With #2, it is the overall experience of driving the car. Before the Magnaflow, my car sounded like any other passenger car (silent). Now it sounds like a muscle car. It'* quiet enough at freeway speeds that I don't notice it. But when I step on it, it screams "lookout!"

When combined with a good K&N air intake, you'll get the most out of your engine. I notice it if I'm already moving at say 40 mph or above, and I step on it to accellerate, like on an entrance ramp or passing a truck. The engine suddenly screams to life and rockets forward.

Hey guys I have a 99 SSEi and I am looking at putting a y pipe before the rear suspension and then hooking up two Borla Turbo mufflers will this help or hurt the car in any way. Another thing are Borla'* really loud?

A.J.

I'm not sure about the Y pipe and turbo mufflers. However, this weekend, I removed the resenator. While adjusting the positioning of the pipes, I pushed up on the exhaust tips and the broke off in my hands. Turns out, the aluminum tips were welded onto metal pipes! Now, I have no tips. In addition, a baffle in the muffler is rattling so now I got to get a muffler. I'm going to go with the 80 Series Crossflow 2.50" O/Opp DUAL by Flow master. 80 Series Cross Flow - Two Chamber Mufflers
The 80 Series is designed for applications where the muffler must be mounted transversely (cross-flow) behind the rearend. It provides an aggressive muscle car sound both inside and outside the vehicle. A replacement for early and late model Camaros & Firebirds. Constructed of 16 gauge aluminized steel and fully mig-welded for maximum durability.

Anyone know of a good manufacturer to get exhaust tips and 2.5" extension pipes off the muffler?

You just buy tips, your exhaust guy bends pipes and welds it all together.
http://www.autobarn.net/raunextip.html
That'* a nice oval tip that I have and several others have.
There have been some REALLY nice dual-tip jobs recently. Just browse the recent posts in the performance section, or do a search on tips.

Well, I had a custom 2.5" pipe bent to match the factory pipe and welded into the Flowmaster 80 series (2.5 in / (2) 2.5" out). The pipe goes from the Cat back (note: factory resonator has been removed). Car sounds like it has a V8 at idle and upto 2K RPMs. However, shortly there after I get the infamous V6 "wrang" sound. There is plenty of vibration and resonance throuhout the cabin up to 4K RPM. After 4K, it seems quieter from within the cabin. If I'm in neutral or park and I rev the engine up, I get the notorious V6 sound, however, upon immediate release of the pedel, I get some banging sounds like back fires. Small little "pops" usually coming down from the 5K RPM range. I believe I'm also getting a lot of rattling coming from the heat shields underneath. I'm thinking that if I put the resonator back on, I can lower the vibrations and eliminate the rattling heat shields.

1) Is anyone having or have dealt with a similar situaion?

2) What are the fixes to this annoyance?

3) Should I put the resonator back on?

Like Will said five posts back, when he said "keep your resonator";
YES, you should put the resonator back on. The annoyances you are describing are precisely what we were warning you about, regarding removing the resonator. Will even ADDED one to his 93 to improve its sound. (His didn't come with one.)

Yes, put it back on.

So what tips did you go with? Pics?

What size is the OEM resonator? Was it 2.5" ? I'm looking around on the net and I see alot of "resonators" that are described much like glass packs. Is there an after market resonator I should go with or can I get one from the dealership without the rest of the piping? Or better yet, would Midas be able to throw one in for me?

On your recommendation, I ordered 2.5" Ractive TCN-T815 Slant/Rolled Edge stainless tips from some guy on Amazon.com ($20 each). I ordered them 5/31, he said he shipped them 6/8, today'* email says I should see them by 6/21. When I get the tips put on, I'll post pictures of the entire system.

Just got word from GM that the resonator for the 99 Bonneville (along with many OEM parts) have been discontinued. I need to find a good aftermarket resonator - any suggestions?