Smog-Checking A Classic: 1979 Dodge Brougham Camper

Smog tests are a requirement for vehicles in California, with similar tests being implemented in other states. All 1976 and newer vehicles need to pass a smog check before being allowed California registration. The 1979 Dodge Brougham Camper falls into this category and so will need to pass a smog test. The emission standards for older vehicles are loose, and the state understands that older motorhomes/RVs produced higher emissions than newer modern motorhomes. With that in mind, there are emission standards in place that will allow an older vehicle to pass the smog test, however, these vehicles must be in moderate operating condition and must not have any emission tampers.

California smog test requirements

California's Smog Check Program is a vehicle inspection and maintenance program designed to improve air quality by identifying vehicles with excess emissions so they can be properly repaired or retired. The program has been in place since 1984 and has significantly reduced air pollution from millions of vehicles in California.

A Smog Check is required every two years as part of the vehicle registration process in California. It is also required when a vehicle changes ownership or is registered in California for the first time.

Gasoline, hybrid, and alternative-fuel vehicles that are model-year 1976 and newer require a Smog Check, with the following exceptions:

• Gasoline-powered vehicles eight model years and newer are exempt from biennial Smog Checks.
• Gasoline-powered vehicles four model years and newer are exempt from change-of-ownership Smog Checks.
• Diesel-powered vehicles model-year 1998 and newer with a gross vehicle weight rating of 14,000 pounds or less require a Smog Check. There are no model-year exceptions for diesel-powered vehicles.

• Gasoline-powered vehicles, hybrid vehicles, and alternative-fuel vehicles that are model-year 1975 and older.
• Gasoline-powered vehicles, hybrid vehicles, and alternative-fuel vehicles that are eight model years and newer are exempt from biennial Smog Checks.
• Gasoline-powered vehicles, hybrid vehicles, and alternative-fuel vehicles that are four model years and newer are exempt from change-of-ownership Smog Checks.
• Diesel-powered vehicles that are model-year 1997 and older.
• Diesel-powered vehicles with a gross vehicle weight rating of more than 14,000 pounds.
• Electric-powered vehicles.

A Smog Check may include the following inspections, depending on the vehicle type and model year:

• Visual inspection of emissions-control equipment and systems.
• Functional inspection of the vehicle’s check engine light, ignition timing, exhaust gas recirculation system, fuel evaporative system, and gas cap.
• Functional inspection of the vehicle’s on-board diagnostic (OBD) system.
• Tailpipe emissions inspection.

Performing regular maintenance according to the owner's manual and avoiding tampering with the emissions-control equipment will improve your vehicle's chances of passing a Smog Check. Additionally, addressing any "check engine" light issues as soon as possible is crucial. A pretest or pre-inspection can also help identify emissions-related problems before an official Smog Check.

Pre-test considerations

Before taking your 1979 Dodge Brougham camper for a smog test, there are several important considerations and preparations to keep in mind. Firstly, it is essential to understand the specific requirements and regulations for smog testing in your state. While California is known for having strict smog testing standards, other states may have similar or varying requirements. Knowing the specific rules and regulations in your state will help you prepare for the test effectively.

Another crucial factor is the age of your vehicle. In California, all 1976 and newer vehicles must undergo a smog check before they can be registered in the state. Older vehicles like your 1979 camper are subject to less stringent emission standards, but they still need to be in moderate operating condition and must not have any emission tampers.

To increase your chances of passing the smog test, it is recommended to perform a pre-test at a smog station. This pre-test does not affect your official results, but it provides valuable insights and helps you identify any potential issues. Keep in mind that a pre-test can be expensive, costing the same as an actual smog test. However, it is worth considering if you want to avoid multiple attempts and reduce the risk of failing.

Additionally, if your camper has been in storage or had its battery removed, you must drive it for at least 200 miles under various traffic conditions to reset the emission readiness monitors. On the other hand, if your vehicle started without any issues, a shorter drive of 20-30 minutes should be sufficient to warm up the engine before the smog check.

Finally, it is beneficial to have a basic understanding of the smog testing process. The test typically involves three components: emissions, visual, and functional inspections. The emissions test measures tailpipe emissions, including hydrocarbons (HC), carbon monoxide (CO), and nitrous oxides (NOx). The visual inspection checks for the presence and functionality of emission control devices. The functional inspection includes checks on timing and idle speed, gas cap sealing, and fuel pipe restrictors.

Vehicle weight and emissions limits

The weight and emissions limits for vehicles are set by the Federal Highway Administration (FHWA) and the Environmental Protection Agency (EPA). The FHWA defines vehicle weight classes from 1 to 8, based on the gross vehicle weight rating (GVWR), which is the maximum weight of the vehicle, as specified by the manufacturer. The GVWR includes the total vehicle weight, as well as fluids, passengers, and cargo.

The FHWA categorizes vehicles as Light Duty (Class 1-2), Medium Duty (Class 3-6), and Heavy Duty (Class 7-8). The EPA defines vehicle categories by GVWR for the purposes of emissions and fuel economy certification. The EPA classifies vehicles as Light Duty (GVWR < 8,500 lb) or Heavy Duty (GVWR > 8,501 lb).

Within the Heavy-Duty class, there is a Medium Heavy Duty Diesel Engine class for engine-only certification, but no Medium-Duty Vehicle class.

Weight Limits

The FHWA's weight limits for vehicles are as follows:

• Class 1: < 6,000 lbs
• Class 2: 6,001 - 10,000 lbs
• Class 3: 10,001 - 14,000 lbs
• Class 4: 14,001 - 16,000 lbs
• Class 5: 16,001 - 19,500 lbs
• Class 6: 19,501 - 26,000 lbs
• Class 7: 26,001 - 33,000 lbs
• Class 8: > 33,001 lbs

Emission Standards

The EPA's emission standards for on-road and non-road vehicles are outlined in the Emission Standards Reference Guide. The standards are based on the vehicle weight classifications defined by the FHWA.

For light-duty trucks (LDT), the emission standards are as follows:

• LDT 1 if loaded vehicle weight (LVW) = 3,750
• LDT 2 if LVW > 3,7500
• LDT 3 if adjusted loaded vehicle weight (ALVW) = 5,750
• LDGT 4 if ALVW > 5,7500

The weight and emissions limits for vehicles in the United States are set by the FHWA and the EPA. The weight limits are based on the GVWR of the vehicle, while the emission standards are based on the vehicle weight classifications defined by the FHWA.

Functional and visual inspection

To smog check a 79 Dodge Brougham camper, you will need to perform a functional and visual inspection. This will involve checking for the presence and functionality of various emission control items installed by the factory. Here is a detailed guide on what to inspect:

Visual Inspection:

Before the test, perform a visual inspection yourself. Check for the presence of the following items:

• EGR switches and valves on 73-74 dual carb systems
• EGR valve and throttle valve switch on early FI models
• EGR mechanical valve on late FI models

Quite often, the muffler has been replaced, and the system removed altogether. In this case, you will need to source the parts or hope the smog tech does not notice. The EGR filter is still available, although it is expensive.

Functional Inspection:

The functional inspection will include a check of the timing and idle speed. The idle speed must be within the manufacturer's guidelines, and the timing must be within 3 degrees of the specification; otherwise, a fail will be recorded. This is a simple tune-up to perform but should be done before the test.

The gas cap will also be inspected to ensure it seals correctly, and a check for the presence of any fuel pipe restrictors will be carried out.

Additionally, the smog techs might test the EGR system. Early EGR systems (73-76) were electro-vacuum operated, while later systems were purely mechanical via linkage to the throttle. To test this, the techs will disconnect the switch/linkage and watch the engine RPMs as they activate it manually.

• Ask the techs to test the timing by clamping onto spark plug wire #1 or #3. If they do not do this, the timing mark will not appear, and you may fail when the timing is within spec.
• The EGR filter to throttle body joint must be properly sealed, and the mating surface profile on the bench should be checked before attachment.
• Gaskets for the EGR valve to throttle body joint are hard to find, but the originals are long-lasting.
• A double gasket at the filter sometimes helps improve the EGR filter to EGR pipe joint seal.
• Adjusting the EGR linkage is relatively easy: undo the 8mm locknuts and shorten the linkage until the idle drops, then lengthen it until the vacuum level increases to maximum and tighten the locknuts.

By performing these thorough functional and visual inspections, you can ensure your 79 Dodge Brougham camper has the best chance of passing the smog check.

Adjustments and tune-ups

Pre-Test Adjustments:

• Battery Check: If your camper has been in storage, check the battery and recharge or replace it if necessary. A well-charged battery will ensure the emission readiness monitors are functioning correctly.
• Engine Warm-up: Before taking your camper for a smog test, ensure the engine is thoroughly warmed up. Drive your vehicle for at least 20-30 minutes to ensure it reaches its optimal operating temperature. This will help reduce the risk of inaccurate smog test results.
• Emission Devices: Inspect all emission control devices to ensure they are present and functioning. This includes items such as the positive crankcase ventilation system, catalytic converter, exhaust gas recirculation (EGR) system, and charcoal canister.
• Fuel System: Check the fuel system for any leaks or issues. Ensure the fuel filler neck, hoses, and fuel evaporative lines are in good condition and properly sealed. A leaking fuel system can result in a failed smog test.
• Idle Mixture Adjustment: Adjust the idle mixture screw to ensure it is within the manufacturer's specifications. This adjustment will affect the air-fuel ratio (AFR) at idle and can impact emissions.
• Timing and Idle Speed: Verify that the ignition timing and idle speed are within the specified limits. Incorrect timing can affect emissions and engine performance.
• Spark Plugs and Wires: Check the condition of your spark plugs and wires. Replace them if necessary to ensure a strong spark, which is crucial for complete combustion and reduced emissions.
• Valve Adjustment: Ensure the engine valves are properly adjusted. Proper valve adjustment can help optimize engine performance and reduce emissions.
• Air Filter, Oil, and Oil Filter: Replace the air filter, and change the oil and oil filter. This will help reduce hydrocarbon (HC) emissions, as clean oil and a fresh air filter promote more efficient combustion.

Post-Test Adjustments:

• Retest and Tune-up: If your camper fails the smog test, don't panic. You will usually be allowed a free retest after making adjustments. Take your vehicle to a qualified mechanic who can diagnose and fix any issues. Common adjustments may include tuning the engine, replacing spark plugs, or repairing emission control devices.
• Exhaust System: If your camper has a catalytic converter, ensure it is in good condition and not clogged. A clogged catalytic converter can lead to increased emissions and affect the performance of your vehicle.
• EGR System: Check the EGR system for proper functioning. A malfunctioning EGR system can affect emissions and engine performance. Ensure the EGR valve is opening and closing at the correct times.
• Fuel Injectors: If your camper has fuel injectors, ensure they are clean and functioning properly. Clogged or faulty fuel injectors can lead to higher hydrocarbon emissions and engine performance issues.
• Air-Fuel Ratio (AFR) Adjustment: Use a wide-band oxygen sensor tester to fine-tune the AFR. Adjust the AFR slightly leaner if necessary, but be cautious not to go too lean, as this can increase nitrogen oxide (NOx) emissions.
• Engine Maintenance: Regular engine maintenance is crucial. Keep your engine well-maintained by checking for vacuum leaks, fuel pump issues, fuel pressure regulator problems, and other common engine problems that can affect emissions.

Frequently asked questions