answersLogoWhite

0


Best Answer

Possibly an O2 sensor malfunction. A majority of the "Emissions" or "Check Engine" light indications are from these sensors, especially if the car still runs well. Newer cars may have two O2 sensors - one before the catalytic converter and one after. It can also be triggered by a loose or missing fuel cap or a leak in the fuel vapor recovery Plumbing, neither of which would cause the engine to run poorly. The best way to find out is to have your mechanic plug in an engine computer code reader and perform a diagnostic test to see what is making the light go on.

User Avatar

Wiki User

14y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What can cause an emissions light to come on?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

Could low power steering fluid cause check engine light to come on a 2005 Honda Accord?

No, the Check Engine light will only come on when you have an emissions related problem.


Will a new battery cause your engine light to come on?

The check engine light comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, a check engine light is lit when there is a problem in the emissions or somthing that is affecting the effectiveness of the emissions.


What would cause the check engine light to come on in a Toyota?

Any fault that affects emissions will turn the light on. You need to have it checked for codes to know possible causes.


Would a hole in radiator cause the emishion light to come on?

No. If your vehicle can pass an emissions test, chances are that it's just a bad sensor.


What causes the service emissions system light to come on on Ford Escape?

There can be several causes for the service emissions systems light to come on in a Ford Escape. The light can indicate an 02 sensor is out or it can indicate an exhaust leak.


Why does your engine light comes on a 2008 Chrysler town and country?

The check engine light comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, the problem is in the emissions or something that is affecting the effectiveness of the emissions, but other causes can trigger the light to come on, too. To determine the cause, the vehicle will need to be taken to parts store or a shop that has an OBD2 scanner.The check engine light comes on and stays on when a problem is detected by the self diagnosis system of your vehicle. Generally, the problem is in the emissions or something that is affecting the effectiveness of the emissions, but other causes can trigger the light to come on, too. To determine the cause, the vehicle will need to be taken to parts store or a shop that has an OBD2 scanner.


What is cause of check emissions light on Renault scenic?

There are multiple reasons the check emissions light may come on in a Renault Scenic. It could be something as simple as the gas cap not being on properly, but it may also be something more expensive like the oxygen sensor.


Why does Toyota Celica engine warning light come on emissions?

The engine warning light for emissions might come on in a Toyota Celica if the Oxygen Sensors are bad. It might also come on if the catalytic converter is not working properly or is plugged.


What could be the cause of a 1999 Oldsmobile intrigue service engine soon light staying on?

Any problem with the car that affects its emissions will cause the light to come on and stay on until the problem has been fixed. (There are literally dozens of possible causes.)


What are the most likely possibilities that will cause the check engine light to come on?

Anything that can change the emissions of the vehicle. Engine sensors, EGR, gas cap, transmission, etc.


Why does emissions light come on?

If the emissions light turns on there is a problem with the exhaust system. The oxygen sensor, erg system and exhaust should be checked for any leaks or malfunctions.


What can cause the check engine light to come on in a 1999 dodge durango?

The light comes on when the computer detects a malfunction that affects emissions or the transmission. You will need to have the codes checked with a scan tool to know possible causes.