Symptoms of a Bad or Failing EGR Vacuum Modulator

Our certified mechanics come to you · 12-month, 12,000-mile warranty

GET A QUOTE Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of Replacing a Bad or Failing EGR Vacuum Modulator

Common signs include engine performance issues, the Check Engine Light coming on, and failing an emissions test. Our certified technicians can come to you and diagnose the problem. You will receive a $30 credit towards any follow-up repairs that result from the diagnostic. Following are example prices for EGR Vacuum Modulator Replacement. Click on the button below to get an upfront quote for your car.

Cars Estimate Parts Cost Labor Cost Savings Average Dealer Price
2005 Chevrolet Optra $184 $114.01 $70.00 16% $221.51
2006 Chrysler 300 $184 $114.01 $70.00 16% $221.51
2007 Mercury Mountaineer $191 $114.01 $77.00 17% $232.26
2007 Lexus ES350 $156 $86.19 $70.00 19% $193.69
2009 Lexus LX570 $184 $114.01 $70.00 16% $221.51
2008 Mercedes-Benz SLK55 AMG $173 $96.21 $77.00 19% $214.46
GET A QUOTE FOR YOUR CAR Get a fair and transparent estimate upfront

How to Diagnose a Bad or Failing EGR Vacuum Modulator?

EGR vacuum modulator

The EGR vacuum modulator is a component found on some EGR systems. It controls the flow of the EGR system by using a vacuum operated diaphragm to increase or decrease EGR flow. When the vacuum is high, combustion temperatures and airflow are naturally lower so the diaphragm will close and restrict flow, when vacuum is low airflow and combustion temperatures are higher, so EGR flow must be increased.

For vehicles equipped with them, the EGR vacuum modulator is one of the most important components of the EGR system. Any issues with it can cause the system to malfunction, which can lead to increased emissions and other problems. Usually a bad or failing EGR vacuum modulator will produce a few symptoms that can alert the driver of a potential problem that should be serviced.

1. Engine performance issues

One of the first problems of a potential issue with the EGR vacuum modulator is engine performance issues. If the EGR vacuum modulator diaphragm tears or leaks it will disable the EGR system and may cause a vacuum leak. An excessively large vacuum leak can result in engine performance issues such as a decrease in power, acceleration, and fuel economy.

2. Check Engine Light comes on

Another symptom of a potential problem with the EGR vacuum modulator is an illuminated Check Engine Light. If the computer detects a problem with the EGR vacuum modulator signal or circuit it will set off the Check Engine Light to alert the driver of an issue. The Check Engine Light can also be activated for a variety of other reasons, so having the vehicle scanned for trouble codes is highly recommended.

3. Failed emissions test

Another symptom of a potential problem with the EGR vacuum modulator is a failed emissions test. Sometimes the EGR vacuum modulator can fail, and not set off the Check Engine Light. This will result in increased NOx emissions, which can cause the vehicle to fail an emissions test if the levels climb too high. This is particularly important for states that require emissions testing for all of their registered vehicles.

While the EGR systems on newer vehicles are being controlled by a wide variety of other methods, EGR vacuum modulators are still commonly found on many road going cars and trucks. They serve an important purpose in the overall functionality of the EGR system and when they fail can cause an increase in emissions. If you suspect that your vehicle’s EGR vacuum modulator may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic to determine if the component should be replaced.

vacuum
Check Engine Light
EGR (Exhaust Gas Recirculation)

Fast and easy EGR Vacuum Modulator Replacement service at your home or office.

GET A QUOTE FOR YOUR CAR
Get a fair and transparent estimate upfront

More related articles

Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P0291OBD-II Trouble Code: Cylinder 11 Injector Circuit Low
P0291 code definition When your vehicle’s PCM registers the P0291 code, it means that a voltage reading came from the fuel injector circuit – for cylinder number 11’s fuel injector –...

Related questions

Q: can cup hands over carburetor when its running and it will not stall

Hello and thank you for your question. Yes, you are right but only if you have completely shut off the air intake at that point. Not sure that cupping your hands will do it but surely you can be the...

Q: What Do Transmission Error Codes Tell You?

Using transmission error codes is a necessary procedure for a transmission technician since automatic transmissions have been computer controlled for over 20 years. The transmissions currently in use are very different to diagnose and repair than transmissions from decades ago....

Q: clear/replace EGR valve

Hello, thank you for writing in. For exact specifications on tools needed and a step by step procedure, you will need to access a service manual for the vehicle. Typically you would expect to use a 12 mm socket or...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com