yes the 3'' dp will still bolt up...as long as you get the bolt in version.it is reduced to 2.5 to bolt up to the stock mani and the stock catback.Shouldnt hurt miliage.cat is for emissions only.The car is slightly louder with a dp and no cat...i couldnt even notice except at lower rpm's...even with full headers i could not tell any difference.I plan on keeping the muflers stock because i dont like the sound a v6 with exhaust gives off

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1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~#4 FMHE~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~ZZP SS Headers~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

so which dp should i go with on a 00 gp gt with slp exhaust?2.5 or 3? and we have emmisions.and want to get rid of u bend.

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Wizaired cai,taylor 8mm wires,ngk tr55 plugs, msd coils.slp power flo exhaust w/gtx tips. future mods:zzp 1.0 pcm,slp headers, zzp hv3 uim runners ,zzp hv tb,gmpp sway bars,kyb agx struts,18"A.R.M:Rogues wrapped in firestone firehawk gt's.that's all performance wise.

I am going to bring this topic back up. I think I am going to order the 2.5 inch bolt in offroad. I haven't decided if I want the 304 stainless or not. Is it really worth the extra $50?

Also, I plan on getting this and then sending in my stock DP and getting the $50 coupon. With that I am going to buy the O2 Emulator. Will I be fine running my car without this for a couple weeks until I get it?

yep. the bank 1 sensor one (right on the rear header) is the only o2 that has anything to do with fueling. the other sensor is only there to tell you if your cat is working or not. so the only thing the o2 emulator is going to do is turn the ses light off. If your planning on keeping that setup for a while and want the resale value to stay up there in case you do want to sell it i'd get the stainless. When i bought the 2.5 bolt in offroad i got mine in stainless.

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1999 Silver GTP~HP Tuners~XP cam~ZZP FS Intercooler~#4 FMHE~ZZP 78mm Billet Throttlebody~LQ4 MAF~Lucas 42.5's~ZZP SS Headers~2.8 MPS~PRJ fuel logs~Ported & Polished S/C~JMB fwi ~Built Tranny-3.29's-7/8's chain-Intense forged Input Shaft~

Running mid-high 12's

Well I really don't plan on selling the DP once its on the car because I won't have a stock one to replace it with.

Check with local scrapyards before you send the pipe back. the cat should be worth about a hundred bucks because of the platnum in them. I saw they were offering the coupon but I would rather have cash.

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98 GTP - slp powerflo cat back, built tranny, AP104s, homemade FWI and intense 180 stat.

One more question. ZZP has the option of adding a rear O2 bung in the offroad pipe. Could I do this instead of the O2 Emulator or will I still have a SES light?

cant u just take the blub outta the dash?

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[SIGPIC][/SIGPIC 99 DARK BRONZEMIST METALLIC GTP SUPERCHARGED SEDAN. --MODS-- FWI, 104 plugs MSD coils and wires, 180 t-stat, dual thrush exhaust, Kenwood complete system 10' Sub ported, raised spoiler, red calis, D/S Baer rotors, Hawk Pads.

I'm sure I could but then when I actually have something wrong I won't know because I won't have a SES light.

The after market cat may or may not set a CEL. Some guys go for months with no light, and some only make it a week. Some never see it. It really seems to depend on the car.

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2004 Impala LS - got some mods
NAIOA Moderator

Making you think twice before picking on Impalas