How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask George H. Your Own Question
George H.
George H., ASE Certified Technician
Category: Acura
Satisfied Customers: 18761
Experience:  ASE Master Tech 15+ years w/L1 Drivability certification
Type Your Acura Question Here...
George H. is online now
A new question is answered every 9 seconds

2004 acura tl: The emissions system light has been..gas cap..tightened

Resolved Question:

I have a 2004 acura tl. The emissions system light has been on for a few weeks. It has come on twice in the past and in the manual it said to check the gas cap and make sure it tightened securely. I did all three times and the light eventually turned, but this time it has not. Any ideas what I am looking at here?
Submitted: 7 years ago.
Category: Acura
Expert:  George H. replied 7 years ago.

Hello I will help you with your question,


Its like the old saying, "you can't tell the players without a program"!!


There are hundreds of causes that the engine control computer would turn the check engine light on. They range from a loose gas cap to a catalyist damaging misfire condition.


If the light is on steady and the engine seems to be running properly the cause is likely not serious. You can drive to your local Autozone or other chain parts store and they will read the codes for you in the hopes of selling you the parts to repair it. There should be no cost to you. If you post the code or codes you get back here I will help you determine the next step to take.



Please let me know if you have further questions about this


Thank you



George H. and other Acura Specialists are ready to help you
Customer: replied 7 years ago.
I haven't had time to go to an auto store to get the codes read yet, but I noticed the coolant/antifreeze is below the minimum level before the car is started. Could this be a cause of the check engine light remaining on? What kind of coolant would you recommend? Sorry for the delayed response. I appreciate the help.
Expert:  George H. replied 7 years ago.

It is possible that a code for the thermostat would set if the coolant is low but unless it is very low I doubt it. You can top off the coolant with a long life silicate free coolant. Open the radiator cap and see if the radiator is low, top it off and top off the overflow tank. If the radiator is low the cause of the leak needs to be found



Customer: replied 7 years ago.

I have peak anti-freeze 50/50 diluted, and it says that is a low silicate, will that work?

Expert:  George H. replied 7 years ago.

Yes that will be fine


Let me know when you get a chance to get the code read





Customer: replied 7 years ago.
Hey I got those codes read, There are 3. p0496, p2240, p0154. Thanks for all the info.
Expert:  George H. replied 7 years ago.

This is not a loose gascap,


The P0496 is Evap high purge flow


The P2240 is Bank 2 sensor 1 high voltage for the A/F ratio sensor


The P0154 is Bank 2 sensor 1 heater circuit malfunction,


You should replace the bank 2 upper A/F sensor. This is the one in front that is easy to get to. Lousy picture but this is right on top near the cooling fan





Ther p0496 could be an open gas cap or a vent valve that is stuck open. Replace the A/F sensor (Honda/Acura brand only) and have the codes cleared then see if the P0496 comes back. If it does the Evap system will have to be investigated at that time



Customer: replied 7 years ago.

The light went off after I started the car yesterday afternoon. It has not come back on. Is it something I should check up on, or let it ride. I didn't do anything to it, it just went off? Thanks for all your help.

Expert:  George H. replied 7 years ago.

If it cleared by itself it means that the system is OK at this time, the weather may have changed enough to allow the monitor to be run and it passed during this test. I would not be worried but the Heater codes are usually an internal short in the sensor much like a filiment in a light bulb that will make good contact then it will be open so the sensor is on its way out but the EVAP code P0496 may have healed itself if the valve will seal now.


I would wait and see, it wont hurt anything except yourt gas mileage and some excess exhaust emissions if you wait until the light comes back. If it lights again recheck the codes and see if they are the same.