Pro Exhaust - Laws on exhaust and emission systems

Exhaust Systems

The exhaust system includes the manifolds, gaskets, exhaust tubing, mufflers, resonators, tailpiping, and supporting hardware. On vehicles manufactured before 1984, the catalytic converters are considered part of the exhaust system only, and not part of the emissions system. Laws and state inspection criteria differ between what is considered exhaust system only and what is considered the emissions system. In short, on vehicles manufactured before 1984 the catalytic converter (if the vehicle was originally manufactured with a catalytic converter then it must have one) will only be inspected visually for cracks or leaks as part of the exhaust system (1984 was the year catalytic converters were required to be standard equipment. Prior to 1984 some manufacturers delivered vehicles with catalytic converters, some did not).

There are also Federal (EPA) laws governing exhaust and emissions systems, as well as county and city rules that may apply.

Some important notes to remember on Texas laws governing exhaust systems are:

1. Texas state inspectors inspect the exhaust system for holes, leaking seams, or patches on the muffler, resonators, exhaust pipe, tailpipe, or catalytic converter.
2. Every motor vehicle shall at all times be equipped with muffler in good working order and in constant operation.
3. The tailpipe should discharge the exhaust at the rear or sides of the "passenger compartment", and not be in a position where exhaust gases could penetrate inside the passenger compartment. Some pickups are equipped with a camper or hard shell cover, this truck modification will be considered as a passenger compartment. The entire structure of a motor home-type vehicle is considered a passenger compartment.
4. Dual exhaust systems may be modified to single exhaust systems and single exhaust systems to dual exhaust systems, provided the modification does not violate requirements concerning exhaust emission systems.
5. State inspectors do not check how loud your exhaust system is, only that it is present, in good condition, and functioning. However, some cities and counties in Texas have ordinances against "loud" exhaust and you could be pulled over, maybe even ticketed. See "Noise and volume" below for more on loud exhaust.

Emissions / Catalytic Converters

On vehicles manufactured on or after 1984, the catalytic converters are considered part of the emissions system. So, on vehicle models 1984 or later the catalytic converters will not only be visually inspected for cracks or leaks, but will also be checked for presence, connection, and in some cities/counties out-the-tailpipe emission gasses are checked while vehicle is under a load (on a dyno). In addition, vehicles 1996 and up have OBD-II that reports trouble codes for the emission system, which will also be checked.

Some important notes to remember on Texas laws governing emission systems are:

1. Texas state law states that 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 NOT remove or intentionally make inoperable within the state of Texas the exhaust emission system or any part thereof, except where the purpose is to install another exhaust emission system or part thereof.
2. On vehicles manufactured before 1996, the vehicle must have at least 50000 miles and have a legitimate reason to remove the catalytic converter or it cannot be removed legally. On vehicles manufactured on or after 1996, the vehicle must have at least 80000 miles and a legitimate reason to remove the catalytic converter or it cannot be removed legally.
3. Federal law, on 1995 and newer vehicles, also requires that vehicle manufacturers warranty the catalytic converter and other specified major emission-control components for 8 years or 80000 miles. Minor emission-control components and emission-related components must be warrantied for 2 years or 24000 miles. This warranty only applies IF:

* Your car or light-duty truck fails an approved emissions test; and
* Your vehicle is within the required warranty period for applicable components; and
* Your state or local government requires that you repair the vehicle; and
* The test failure does not result from misuse of the vehicle or a failure to follow the manufacturers' written maintenance instructions; and
* You present the vehicle to a warranty-authorized manufacturer representative (such as the car dealer), along with evidence of the emission test failure.

For the full details on Federal law and this warranty, click here.

Noise and volume

Is my exhaust too loud? The answer we all know is subjective. Some of us like our vehicles quiet, some of us like it loud, and all variances in between. While you might think your vehicle sounds great and isn't too loud, a neighbor's definition of "loud" may differ greatly. Don't worry, we think it sounds great too!! However, some counties and cities have their own ordinances against noise levels in dB (decibels). The state of Texas doesn't regulate exhaust noise levels, but you'll have to research the ordinances that apply in your city or county. That being said, most of us do not carry around dB or noise meters, and most law enforcement officers probably don't either, so it is the opinion of a complaintant or a law enforcement officer that ends up mattering in many cases. Some towns are tougher on loud exhaust, some don't care as much, it's up to you to use your best judgement on how loud is "too loud" for where you live and work.

State Inspection exhaust related "rejection" items

Texas state inspectors FAIL the exhaust system for:

Holes, leaking seams, or patches on the muffler, resonators, exhaust pipe, tailpipe, or catalytic converter.
Vehicle is not equipped with a muffler.
Any joint is loose or leaking, including manifolds. Does not include minor leakage at exhaust control valve (manifold damper or heat riser valve).
Manifold is cracked or broken causing leakage.
Exhaust system is not secured to the vehicle by mounting brackets designed for exhaust systems (wire or a coat-hanger is not acceptable).
Any brackets are loose, broken, or missing.
There is excessive vibration of exhaust line.
Any part of the exhaust system passes through the passenger compartment.
The tailpipe is broken, pinched, or eroded off to the extent to allow exhaust fumes to penetrate into the interior of the passenger compartment.
The tailpipe fails to discharge exhaust from the rear or sides or top of the passenger compartment of the vehicle.
NOTE: Holes in the exhaust system made by the manufacturer for drainage are not cause for rejection.
The exhaust emission system has been removed.
The exhaust emission system has been disconnected.
The catalytic converter has been removed, leaking, or disconnected on a 1984 or later model vehicle.
The exhaust emission system has been altered in any manner to make it ineffective.

Texas State Inspection full list of items checked - CLICK HERE

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