Question on exhaust

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tri94sbc

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Before I start tearing apart my daily driver and putting headers and new pipes on her, I just want to know something. If I drop the cat do I need to keep the oxygen sensor connected and if so will this affect the on board computer ? If so what should I do ? Working with a lot of desire and very little knowledge.

:hmmm2:
 

Gzes

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Theres a silverado my buddy wants me to sell for him. Its got no cats and just throws off a code. Works fine but just has the check engine light. Hes got a 96
 

schiavonske1013

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Like Sun said, you'll lose backpressure and you'll most likely feel it when you hit the gas. Removing them also tends to lead to a more raspy sound than a deep rumble, but that all depends on the sound you like.
 

McFizzl

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If you cant resist taking the cats out atleast get a few of these http://www.afterthoughtsauto.com/o2sim.html and it will make your engine run right. I believe without them it will lean out the fuel and cause lots of problems. If its sound you want get high flow cats. Still pass emissions as well and keep backpressure and gain power.
 

SunlitComet

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Theres a silverado my buddy wants me to sell for him. Its got no cats and just throws off a code. Works fine but just has the check engine light. Hes got a 96

no it does not work fine.

---------- Post added at 09:12 PM ---------- Previous post was at 09:00 PM ----------

If you cant resist taking the cats out atleast get a few of these http://www.afterthoughtsauto.com/o2sim.html and it will make your engine run right. I believe without them it will lean out the fuel and cause lots of problems. If its sound you want get high flow cats. Still pass emissions as well and keep backpressure and gain power.


and when he goes for his inspection/emissions testing, WHAMO! busted by tampering and removing with a federally required device. the tbi has one sensor to help the fuel trim for the whole engine. dont mess with it. if you want some good street legal mid lengths with a y-pipe there are one or two sets out there. it bolts to the engine and the other end usually fits to the front of a cat pipe with an adapter and clamps. keeps your O2 sensor increases power and fuel mileage. of course there are shorties too if cost is a major decision variable.
 

McFizzl

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Wanna stay legal? Just keep the cats. They aren't problematic on these trucks like the first converters were that clogged all the time. If yours ever do get clogged you can clean them(little known fact). Soaking in some warm soapy water and spraying them out does wonders. If you change cats check out your state laws and find one that complies with those laws. Better legal than ticketed. Oh and another thing! Just go down to a muffler shop. They are bound to have some high flow cats that comply with emissions for sure.
 
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tri94sbc

tri94sbc

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Thank you all for the input. I was told that my 94 no longer would be emission tested in NY and I'm glad I decided to ask my fellow enthusiasts before I started cutting stuff out. I'm thinking high flow cats will be included in the mix. I believe there is only one oxygen sensor on this year.
 
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Gzes

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Yep 1 o2. I for one am gonna just cut it out. Tx doesnt require emmissions and honestly i dont like cats. My del sol wont have cats neither. Im still gonna run a muffler so it wont be crazy loud but the small change in back pressure doesnt bother me. I also have a 94

---------- Post added at 07:06 AM ---------- Previous post was at 06:24 AM ----------

Im gonna run a dummy 02 to cancel the check engine light
 

SunlitComet

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Thank you all for the input. I was told that my 94 no longer would be emission tested in NY and I'm glad I decided to ask my fellow enthusiasts before I started cutting stuff out. I'm thinking high flow cats will be included in the mix. I believe there is only one oxygen sensor on this year.
currently on the books in NY, Gas cap presence and Anti-tampering visual checks for: 25 model years old to Model Year 1995, up to 18,000 lbs. GVWR.
which means they look at all emissions equipment.

---------- Post added at 10:10 AM ---------- Previous post was at 09:46 AM ----------

Yep 1 o2. I for one am gonna just cut it out. Tx doesnt require emmissions and honestly i dont like cats. My del sol wont have cats neither. Im still gonna run a muffler so it wont be crazy loud but the small change in back pressure doesnt bother me. I also have a 94

---------- Post added at 07:06 AM ---------- Previous post was at 06:24 AM ----------

Im gonna run a dummy 02 to cancel the check engine light


actually they do just currently not in your county but if you end up in one of these county: Brazoria, Collin, Dallas, Denton, Ellis, El Paso, Fort Bend, Galveston, Harris, Johnson, Kaufman, Montgomery, Parker, Rockwall, Tarrant, Travis and Williamson, you are required to have the emissions done.


20.14 Exhaust Emission System.
Operator of the motor vehicle or motor vehicle engine shall not remove or intentionally make inoperable within the state of Texas the exhaust emission system or any part thereof, except where the purpose of removal of the exhaust emission system or part thereof is to install another exhaust emission system or part thereof, which is intended to be equally effective in reducing atmospheric emissions from the vehicle or engine.
The exhaust emission system was installed by manufacturers of motor vehicles beginning with model year 1968. The inspection of the exhaust emission system will apply only to those vehicles that are equipped with such a system. The following exhaust emission systems will be inspected if installed as original equipment by the manufacturer: thermostatic air cleaner, exhaust gas recirculation system, positive crankcase ventilation system, air injection system, evaporative emission system, and/or catalytic converter.
If installed as original equipment by the manufacturer, the catalytic converter will be considered a part of the exhaust emission system on all 1984 and later model vehicles. It will be inspected as a part of the exhaust system on prior to 1984 model vehicles.
1. Inspection Procedure. Examine visually.
2. Inspect for and reject if:
a. The exhaust emission system has been removed.
b. The exhaust emission system has been disconnected.
c. The plumbing or hoses are loose, broken, leaking, or improperly routed.
d. Air pump (air injection-type) belt is loose, removed, excessively cracked, frayed or has pieces missing.
e. The exhaust emission system has been altered in any manner to make it ineffective.
f. The catalytic converter has been removed, leaking, or disconnected on a 1984 or later model vehicle.
3. Gas Cap Testing. Every gasoline-powered vehicle* from 2-24 model years old will be checked for presence of and by a Department approved "Gas Cap Testing Device" to determine if the gas cap is missing or defective. The following vehicles are exempt:
a. Antique vehicles.
b. Slow-moving vehicles.
c. Motorcycles.
d. Vehicles operated exclusively by a fuel other than gasoline.
e. Vehicles newer than 2 years old and older than 24 years old.
4. Inspection Procedure.
a. Conduct daily calibration check of gas cap testing device.
b. Check for presence (all gas caps must be checked).
c. Check for correct type of gas cap(s).
d. Remove gas cap(s) and test using an approved testing device. (Gas cap present but not testable will not be cause for rejection.)
e. Any gas cap(s) failing the initial test will be tested a second time to verify failure.
5. Inspect for and reject if:
a. Vehicle not equipped with required gas cap(s).
b. Vehicle not equipped with proper type gas cap(s).
c. Gas cap(s) fails both tests.
A motor vehicle that uses liquefied petroleum gas that is operated by a public school district or county in this state is not required to have a liquefied gas tax decal or special use liquefied gas tax decal. Vehicles using liquefied petroleum gas as fuel or a combination of liquefied petroleum gas and any other fuel must bear a liquefied gas tax decal on the windshield lower right-hand corner showing this vehicle uses liquefied petroleum gas, before a safety inspection certificate can be issued.The inspection of the exhaust emission system shall not apply to motor vehicles altered and modified to use only a fuel other than gasoline. The owner or operator of any new motor vehicle or new motor vehicle engine beginning with the model year 1968 equipped with an exhaust emission system shall maintain the exhaust emission system in good operable condition and shall use it at all times that the motor vehicle or motor vehicle engine is operated.
NOTE: When a vehicle is presented for inspection and the vehicle is from a designated emissions county and is subject to the Texas Vehicle Emissions Inspection and Maintenance Program an Affidavit (VIE-12) is required. (See Chapter 5, page 5-14.)


Regardless of the state law the converter laws are federally mandated law. and unless your county an state wrote and put in place a law to reject it(super unlikely) it must still be complied with. just becuase they might not look for it at the moment does not mean it is okay to tamper with it.

Period. no if and or buts about it. i keep trying to tell you this and also it hurts from a personal health and vehicle performance standpoint as well.

just do the right thing and you will be better off for it. you want to change sound do it with a muffler or headers but not mess with the cat. other wise when day you will get caught and get in trouble then your gonna be like this:
scared_cat.jpg
 
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tri94sbc

tri94sbc

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I agree with SunlitComet. I saw some in the Jegs catalog for $67.53 each. 2 1/2" in and out slip fit. (Magnaflow) http://www.summitracing.com/parts/mpe-53006/media/images
They're 13" long and made of stainless steel. I'm diggin the legal ramifications. Stay away from trouble is good for me. I want to put ****** Headers in front and Cherry Bombs on the other end of them.
 

SunlitComet

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then dont bother saying so. if you think you have the correct information then say so. otherwise please don't post in a thread that something in a thread epic fail and not back it up.
 

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