The install was a snap, even with 110K miles on the car. I have been putting penetrating oil on the DP bolts and O2 sensors every day for the last week. Everything came off so easily. I forgot to go rent a O2 socket from Autozone until the car was in the air, so I jumped on the motorcycle and went for a little ride. The sound is much deeper and louder. Since I had the resonator taken off when I first bought the car, the sound is now rather raspy in my car with my summit race welded mufflers. I will have the wife drive it by the house and see how it sounds. I will give it a few days to see if it grows on me, but I will probably end up getting a high quality glass pack welded in. I will be installing one on my wifes Monte Carlo probably Wednesday. I will post how hers sound with no resonator and straight thru magnaflows. I know here resonator was much more restrictive than the one on my GP, so it needed to come off anyway. Here is a pic of the old and the new.

http://picasaweb.google.com/72chevman/CarStuff/photo#5181488357015073762

I put a DP on my wife's Monte Carlo SS today. It has Magnaflow straight thru mufflers with no resonator and 2.5" piping. The sound stayed much the same but louder. It is not as raspy as the GP with it's chambered mufflers. I will say the GP sounds bad arse at idle, but aweful when it is cold and your accelerating. My wife drove it to work this morning and ICK did it sound bad as she left the house and accelerated easy up to 40 on our road. I am doing a glasspack ASAP.

NICE !! i wish i had a new dp!!

Looks very nice! Did you go with the 304 stainless or the DP or no? I think I'm going to just because I don't want it to rust out in a few years but I'm not sure if stainless over the base material will make that big of a difference.

awesome dude!

It seems like the more flow you put through aftermarket muffs makes these cars sound worse and worse.

I did not go with stainless. This pipe gets hot enough that I don't think rust will be an issue, unless you don't drive it everyday. The factory pipe is double wall, so the inner is probably 3/8-1/2 inch smaller OD than what you see, so yes, I got more flow. I cut the inlet pipe off my old cat and it looked pretty good from the front.

I got the stainless zzp cat w/ flex dp.

Definately deeper. I am concerned about passing emissions. The "high efficiency" term only applies to exhaust, not cat's reduction of NO and CO.

Overall, I am happy with my results. Friend aren't used to the sound and they think the car sounds like a bucket. But then they drive in it.

If you are concerned about passing, 1st swap back in your 195 t-stat or block 1/2 your radiator with cardboard to get your engine hot. Make sure you have drive for 20 or so minutes before you get there, so your cat and engine is good and hot. Change your oil just before you go in. Any oil that is blow by and burned will be clean oil and will not read as bad. If you are still close, change your plugs. Oh yeah, get tested just before rush hour on a clear and breezy day. That way the air your car is burning is as clean as it can be, before you test. These are all tricks I remember from living in Southern California. I had a built 355 in my Chevelle and could always squeek by.

sick, im gettin my zzp dp in a couple weeks, what penetrating oil did you use?

I use Valvoline Synpower penetrating lubricant. It is discontinued now. What I liked about this stuff is that it is really thick. I think it stayed on longer to work it's way in, unlike WD-40 or other penetrating oil. I bet almost any would actually work though, even good old motor oil. Just be aware of the smell you will get each time you drive it. The valvoline was pretty bad, but hey, it was worth it.

i know this is a dumb question but....wouldnt oil on the dp cause a fire?

Not a few drops. The DP would have to be REALLY HOT to catch the oil on fire. Have you ever seen a POS car that leaks oil everyhere? It smells and smokes, but no flames.

I've seen more Ford 300 inline 6s that probably have more oil on the outside than on the inside.

the more flow you put through the exhaust the worse it is gonna sound. Headers make it horrid.

Cheer up ordonez, pessimism doesn't suite you well.

The wife's car with magnaflows and 2.5 custom cat back sounds awesome. The chambered muffs sound bad to me, but some may like them. I will try and do a sound clip tomorrow.