Why did my car fail the smog test?

Table of Contents

Why did my car fail the smog test?

The vehicle has approx. 200K miles. (the odometer is broken) It seems to start and run fine, but it failed to pass a California smog inspection.

What causes a 1994 Chevy C / K 1500 to bog down?

– CarGurus 1994 Chevy C1500 5.7 bogs/backfires when I give it gas. My truck bogs down (and tries to die) when I give it gas to accelerate off of a stop. There is often a backfire or two when this happens. Pumping the gas does not help. I basically have to crawl through any intersection until it picks up a bit of speed from idle. The truck

Can a Chevy C / K 1500 run at idle?

There is often a backfire or two when this happens. Pumping the gas does not help. I basically have to crawl through any intersection until it picks up a bit of speed from idle. The truck idles smoothly, and it runs fine once it’s above about 5-10mph or so. If moving at a picking up the speed.

What causes engine hesitation and stumble problems on the 90 +?

Then it developed an intermittent hesitation problem- you would be cruising at 60mph, on a 400 mile trip, ease off the gas pedal, and suddenly for 1/4 second, it was as though someone had switched off the engine and then turned it back on again. The car would then run faultlessly for the rest of the trip.

Why was my NOx too high on the smog test?

The only emission that was above the limit during the smog test was NO, however both HC and CO measurements were about halfway between “average” and maximum. A 2nd website said, “High NOX emissions are almost always due to a defective EGR valve (or some component that controls the operation of the EGR valve).

What was the cause of the stumble engine?

As with engines before the days of Electronic Fuel Injection (EFI), stumble had two basic causes- incorrect ignition and incorrect fuel/ air mixture for the required operating condition.

What can cause a car to fail a smog test?

Dirty oil in the crankcase could release additional pollutants, which could cause the car to fail the smog test, says Asmerian. While the mechanic is changing the oil, ask him to do a visual inspection of the car’s engine to see if any hoses are cracked, broken or disconnected.

When to do a tune up for a smog test?

4. Do a tune-up two weeks before the smog test. Have any required maintenance performed well before the smog test, Mazor says. Most mechanics disconnect the battery while doing a tune-up and this resets the car’s onboard computer. The car then needs two weeks of driving to run all the diagnostic tests needed to pass the smog test.

How often was smog alert in Los Angeles?

“I can remember crying during recess in elementary school because the smog levels were so high,” says Steve Mazor, chief automotive engineer with the Automobile Club of Southern California. He adds that in the 1960s, Los Angeles had 100 smog alerts each year.

Why does my GMC pickup truck use so much oil?

The AFM system, which disables some of the engine’s cylinders at lower RPMs to reduce fuel use, is the most common cause of this issue. While the system accomplishes this, it also leads to oil use problems. Some drivers have reported using as much as a quart of oil every 1,000 miles.

What to do if your smog test is too high?

1. Check for fuel control by watching O2 sensor operation. 2. Check the EGR system for proper operation. 3. Perform a catalytic converter efficiency test. 4. Repair as required. I’m a CA Smog Tech, so post or PM me if you need additional help or direction. Sounds like you just repeated what Mike said.

When to replace the PCV filter and housing?

Replace the PCV valve and check the filter and housing after 500-1000 miles, continue on if the PCV valve is properly functioning or replacing it doesn’t solve the problem. Consider the vehicles routine maintenance schedule.

When does the idle air control valve change?

When the engine is running but the vehicle is not moving, this means the engine is idling. During this time, the number of revolutions per minute (RPM) inside the engine will change. The idle air control valve is responsible for managing the engine idle speed.

Why does my new air filter have rough idle?

Check all of the plastic tubing and hoses from the airbox to the throttle body. Based on the age and mileage it is very likely that something cracked or split and is causing a vacuum leak. It may have pre-existed and the dirty filter blocked enough air to hide the vacuum leak until the new filter flowed more air.

Why does my car idle at high idle?

If this tube becomes loose or broken it can leak un-metered air into the engine effectively causing an unbalance (via the mass air flow MAF sensor) in the computer system which can produce fast or slow idle.

Why did my oxygen sensor fail the smog test?

Failure to pass smog. According to the EPA (Environmental Protection Agency) and CARP (California Air Resource Board) 50 to 60% of all smog test / emission test related failures are attributed to defective oxygen sensors, causing either low or high CO emissions.

Car has 50,000 miles and is in flawless shape- always serviced and use best synthetic oil and premium gas. he said computer need to reset itself since i only drove it since recharge. I trust smog guy – have used him for 15 years; he told i need drive on freeway for 25 miles before taking it in so it resets. I only drive it 5 to 10 miles per week.

What do you need to know about Nevada smog check?

Smog Check in Nevada SUMMARY: Nevada Emissions Control Program The Nevada Department of Motor Vehicles (DMV) oversees the Nevada Emissions Control Program, including which vehicles require testing, how to complete a vehicle inspection, and how to apply for waivers if a vehicle fails an emissions test.

How old does a car have to be to be exempt from smog?

Vehicles model year 1968 and newer UNLESS the vehicle meets the requirements for a Classic Vehicle Exemption. New vehicles on their 3rd registration or later. Hybrid vehicles are exempt for their first 5 model years. Your vehicle’s emissions test is valid for 90 days. For questions about testing locations,…

What is the diagnostic code for a Honda check engine light?

Refer to our Generic OBD II code list for definitions on all other Honda diagnostic trouble codes. P1201 Cylinder 1 Misfire – Compare possible causes/symptoms for this Honda check engine light code to the Generic OBD II code P0301

What is the DTC code on a Honda Accord?

MIL will indicate DTC’s by outputting a number of flashes. Remember, these are manufacturer specific codes only. Refer to our Generic OBD II code list for definitions on all other Honda diagnostic trouble codes. Manufacturer Specific Codes P1106BARO Circuit Range/Performance Malfunction P1107BARO Circuit Low Input P1108BARO Circuit High Input

Refer to our Generic OBD II code list for definitions on all other Honda diagnostic trouble codes. P1201 Cylinder 1 Misfire – Compare possible causes/symptoms for this Honda check engine light code to the Generic OBD II code P0301

What causes a car to fail an emissions test?

A bad MAP sensor will cause your vehicle to fail an emissions test. Your tailpipe emissions may show a high level of hydrocarbons, high NOx production, low CO2, or a high level of carbon monoxide.

Can a bad MAP sensor cause a failed emissions test?

A bad MAP sensor will cause your vehicle to fail an emissions test. Your tailpipe emissions may show a high level of hydrocarbons, high NOx production, low CO2, or a high level of carbon monoxide. A properly trained technician like those at YourMechanic are capable of diagnosing and repairing a failed MAP sensor.

In other words, in most cases, when an emission monitor setting problem has been identified by BAR or CARB, the smog machine is already programmed to bypass the testing of said monitor.

What to do if your EGR monitor is not running?

Start with making sure your vehicle has no known EGR monitor setting issues identified by the BAR and CARB, and next get in to hands-on diagnosis of what is causing the monitor to either not run or not complete. Since the check engine light is not on, we can be confident the ECU has not found any specific emission component failure.

Can a smog monitor be replaced on a car?

The EGR monitor can not be replaced, in that it is not a smog component. Emission monitors are internal self-tests which the Engine Control Unit performs to ensure a vehicle is not polluting and is running efficiently. The entire process of self-testing various emission control systems is called a Drive Cycle.

How does exhaust gas recirculation ( EGR ) work in an engine?

In internal combustion engines, exhaust gas recirculation (EGR) is a nitrogen oxide (NOx) emissions reduction technique used in petrol/gasoline and diesel engines. EGR works by recirculating a portion of an engine’s exhaust gas back to the engine cylinders.

Can you pass emissions with the EGR block off?

Depends on how comprehensive the inspection is. If they just check for any codes in the ECU and do a tailpipe sniffer test then chances are you’ll be okay. Leaning the fuel out may not be the right answer. The A/F needs to bounce back and forth around 14.7 for the cat to work properly. Leaning the fuel out may not be the right answer.

The EGR monitor can not be replaced, in that it is not a smog component. Emission monitors are internal self-tests which the Engine Control Unit performs to ensure a vehicle is not polluting and is running efficiently. The entire process of self-testing various emission control systems is called a Drive Cycle.

Start with making sure your vehicle has no known EGR monitor setting issues identified by the BAR and CARB, and next get in to hands-on diagnosis of what is causing the monitor to either not run or not complete. Since the check engine light is not on, we can be confident the ECU has not found any specific emission component failure.

In other words, in most cases, when an emission monitor setting problem has been identified by BAR or CARB, the smog machine is already programmed to bypass the testing of said monitor.

The vehicle has approx. 200K miles. (the odometer is broken) It seems to start and run fine, but it failed to pass a California smog inspection.

When does Smog Check Come Out the tailpipe?

It does not test what is going on when the engine is cold, idling, decelerating, etc. Also, not all the smog a car makes comes out the tailpipe.

The only emission that was above the limit during the smog test was NO, however both HC and CO measurements were about halfway between “average” and maximum. A 2nd website said, “High NOX emissions are almost always due to a defective EGR valve (or some component that controls the operation of the EGR valve).

1. Check for fuel control by watching O2 sensor operation. 2. Check the EGR system for proper operation. 3. Perform a catalytic converter efficiency test. 4. Repair as required. I’m a CA Smog Tech, so post or PM me if you need additional help or direction. Sounds like you just repeated what Mike said.

Can a Honda Civic fail an emissions test?

[…] site that specializes in explaining the way a car runs created the article “DIAGNOSE – EMISSIONS TEST FAILURE (Smog Check failure)” to help explain why a car can fail an emissions test and require emission […] Failed emissions 1994 Honda Civic SI -1.6 ltr. – HELP!!!!! – Honda-Tech says:

What does it mean when a car fails an emissions test?

The vehicle has failed an emissions test or the exhaust emissions are too high as measured by an emissions analyzer. Emissions or smog is a generic term used to describe certain harmful gases in the exhaust.

What can cause a car to fail a smog check?

Contaminated oils are high in Hydrocarbons (HC) and will present a rich mixture to the engine chambers. Avoiding oil changes not only causes pre-mature engine wear but can also cause your vehicle to fail the smog inspection. Change the engine oil.

How do you pass the smog test in California?

Without these required Emission Monitors your vehicle can not pass the smog test. You will be required to drive between 100-200 miles and over the course of a week, called a Drive Cycle, in order to “complete” the emission monitors and be allowed to pass the smog check.

When to hold off on the smog check?

– If your vehicle recently needed a jump start or battery replacement we recommend holding off on getting the smog check for at least one week. Whenever a vehicle’s computer (engine control unit) losses power, such as when it’s battery has been disconnected or charge depleted, its internal self-test monitors are erased.

How long do you have to warm up your car before the smog test?

Remember your engine is a fuel burning machine. To ensure proper combustion it needs to have sufficient time to warm-up and this can be accomplished through driving for at least 10 to 15 miles. 3.

Can a car pass with only one smog monitor?

Note that a car can pass with some incomplete monitors…a maximum of one on 1999 and earlier cars, and only one ( The Evaporative System monitor) on model year 2000 and later gasoline powered automobiles. All monitors must be complete on 1998-2006 diesel powered vehicles.

It does not test what is going on when the engine is cold, idling, decelerating, etc. Also, not all the smog a car makes comes out the tailpipe.

Why is my smog check OBD 2 incomplete?

There are several reasons why the monitors may be incomplete. If your car has recently been repaired for a problem that set a DTC (check engine on) and the technician cleared the DTC, he also erased the monitors. Also, if battery has been disconnected, replaced or needed a jump-start, the monitors may be erased.

What happens when your car fails a smog test?

When your car gets a smog test, one portion of the test involves connecting the smog test machine to the car’s computer and checking if there are any DTC’s, and also checking to see if the monitors are ready. If they are not, the vehicle fails the test, because there may be problems in the system that can’t be reported by the computer.

Note that a car can pass with some incomplete monitors…a maximum of one on 1999 and earlier cars, and only one ( The Evaporative System monitor) on model year 2000 and later gasoline powered automobiles. All monitors must be complete on 1998-2006 diesel powered vehicles.

There are several reasons why the monitors may be incomplete. If your car has recently been repaired for a problem that set a DTC (check engine on) and the technician cleared the DTC, he also erased the monitors. Also, if battery has been disconnected, replaced or needed a jump-start, the monitors may be erased.

What to do if catalyst is not ready for emission test?

Catalyst Not Ready For Emission Test? Cat Monitor “Inc” ? GET Catalyst Monitor Ready -EASY If playback doesn’t begin shortly, try restarting your device. Videos you watch may be added to the TV’s watch history and influence TV recommendations. To avoid this, cancel and sign in to YouTube on your computer.

How long does it take to complete a diesel smog test?

Any two (2) monitors may be incomplete on 2007 and newer diesels. Some tests only run when the car sits overnight, or is allowed to cool down for several hours. Most cars will complete the monitors easily with the above methods, but rarely it will take up to several weeks before they are complete.

Car has 50,000 miles and is in flawless shape- always serviced and use best synthetic oil and premium gas. he said computer need to reset itself since i only drove it since recharge. I trust smog guy – have used him for 15 years; he told i need drive on freeway for 25 miles before taking it in so it resets. I only drive it 5 to 10 miles per week.

What kind of vehicle is required for smog check?

1 Gasoline-powered vehicles model year 1975 and older. 2 Natural gas-powered vehicles weighing over 14,000 lbs. . 3 Diesel-powered vehicles that: Are model year 1997 and older. OR Have a gross weight rating of over 14,000 lbs. 4 Electric vehicles. 5 Motorcycles.

How many miles does a smog test take?

This can take anywhere from 100 up to 500 miles of driving as long as it is varied as I mentioned. If you would like to get an estimate for this, you can enter your vehicle information on our estimator page to get a quote.

How old does a car have to be to get a smog exemption?

Similar to transferring vehicles, selling vehicles does not require smog certifications for gasoline-powered vehicles 4 years old or less*; the new owner will pay the smog transfer fee. Diesel-powered vehicles are not included in this exemption.

How many miles does a 2011 Saab 9-3 drive?

No accident or damage reported to CARFAX. 1st owner purchased on 08/17/11 and owned in IN until 06/17/13 • 2nd owner purchased on 09/24/13 and owned in KY until 04/28/21. 1st owner drove an estimated 13,131 miles/year • 2nd owner drove an estimated 12,713 miles/year.

When was the last time I serviced my Saab?

Last serviced at 54,452 miles in Houston, TX on 07/10/20 • Vehicle serviced • Cabin air filter replaced/cleaned • Fluids checked • Oil and filter changed • Tire condition and pressure checked • Cabin air filter checked. No accident or damage reported to CARFAX. Purchased on 02/10/11 and owned in MA until .