Chris 611

If I was to disconnect the AIR system on my ’91 Formula 350 what headers could I get? In other words, what year firebird headers can I look at buying? I will need the O2 fitting also, but am not so concerned with the Y - pipe. I was going to run with CAT, but not the style that require the AIR system. I assume they make that type of CAT since some vehicles have converters, but not AIR. Any help would be greatly appreciated. Thanks.

Chris

five7kid

iTrader: (14)

I'm not sure you're on the right track here. The y-pipe is a very important piece of the puzzle - getting one that goes with the headers will be much cheaper than having one fab'd later, and probably better quality.

Why are you going with a cat if you're willing to eliminate the AIR? If you need the cat for emissions, you'll need the air, too. It doesn't make an appreciable power difference, and does help clean up the exhaust. Keep it on there.

Hooker, Hedman, Edelbrock, SLP all make good quality pieces that include AIR, O2, & y-pipe. Give 'em a call, tell 'em what you've got and where you're going, they'll take care of you.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. 0.030 over 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlock header mufflers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, LT MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1/95.5 @ 5800' Bandimere.

Suaveat69

take off the cat and run the headers. the air crap does nothing to clean the air excapt dilute the gasses at startup. like cars pollute the air.

LeftTurn1LE

I agree with five7kid. Might as well keep the AIR system if your going to keep the cats. Its controlled by ECM so sure removal would be unwise.

LeftTurn1LE

Sorry, double post.

[This message has been edited by LeftTurn1LE (edited June 26, 2001).]

shutch

i'm running headmans in my 87 iroc, no AIR tubes, high flow cat, and no problems whatsoever. then again, your's is sd so what would i know

Chris 611

My main reason for leaving the CATs on is so I don't upset the O2 sensor. I though I remember someone telling me that if the CAts aren't there, the O2 sensor tries to compensate by changing the A/F ratio and this can cause other problems. Please correct me if this isn't true. Thanks.

b92z28

slp 1 3/4 headers no air or cats and true 2 1/2 duals. no check engine light and the o2 is still working properly. but of course i dont get inspected either.

------------------
92 z28 170,000 miles 14.20 on goodyear eagles before exhaust only mods k&n and slp 13/4 headers and dual 2 1/2 exhaust
87 trans am 12.20 on motor too many mods to list

LeftTurn1LE

The O2 sensor is before the cats and removing them would not affect the sensor.

[This message has been edited by LeftTurn1LE (edited June 26, 2001).]

cheviroc87

i actually use the summit brand cheap-*** headers, they come black painted and have a o2 fitting.
i had the ceramic coated-and no one can tell they only cost me 80 bucks, haha

Curse Z28

The only vehicles that have o2 sensors affected by removing cats are OBDII cars, they have O2's before and after the cat.
ALL thirdgens are OBD-I and removing the cat will NOT interfere with computer operation or sensors.

AJ_92RS

I just heard from a UTI graduate that we are gonna have emissions testing in my area soon. He said that since I have the OBD-I system on my car, that all I will have to do is pass the sniffer. Is that true. Do any of you guys have to pass emissions testing that requires a visual check, or is it just a sniffer? And does it depend on the state you live in? And I don't mean a state of insanity either. We all live there!! HEHE!!

I want to yank the AIR system just for the simple fact of the lines being in the way of a tune-up, plus they're ugly. From what I've understood so far, removing them won't make any change in the sniffer reading. Is that right. If so, I'm getting NON-AIR headers. Why **** with it if you don't have to?

------------------
92 RS w/t-tops 305 TBI Auto.
170K miles and don't burn a drop o'oil
-K&N Truck filter #1500 w, open ele.
air cleaner
-Dynomax 2 1/2" cat-back
-B&M TransPak
-Jet Stage2 Chip
-180* T-Stat w/ 185* Fan Switch
-JVC CD--Alpine speakers & 4ch. amp
Rockford 2ch. to 2 MTX 12" subs

AJ_92RS

3 tees

whiterocz

in my opinion, the whole air system is a waste of metal. does absolutely no good on a properly well tuned car. removing your cats on a thirdgen wont mess with the o2 sensor at all because it reads before the cat. on fourth gen f-bodies they have o2 sensors before and after the cats.