Skip the auto shop - Our mechanics make house calls

Q: Check Engine Light is on - 2003 Honda Accord

asked by on

The check engine light is on. This is the second time. I had it cleared the first time. Both times I noticed that it went on after I turned on A/C and same time turned to heat to defrost the window. The window is easily get foggy inside even on a not so wet day. I did some research online and I think the symptom is somewhat matches with that of the vacuum leak. My car is always jerky when I push the gas pedal, but it's still very powerful and no problem with accelerating at any speed. I can hear a hissing sound when I touch on the accelerating pedal. Could you help me to diagnose it? When I drove it to mechanics, they told me it's the Catalytic converter failed which I am not convinced because it is not matching the symptom of a failing catalytic converter. Thanks. Cindy

My car has 170000 miles.
My car has an automatic transmission.

A: Hello. If the issues appeared when using th...

Hello. If the issues appeared when using the AC and defroster, then they are likely related to that system. In most cases, the AC / Heater does not use vacuum lines as a part of it’s operation, so a vacuum leak is not a likely a cause for your symptoms. However, there are some exceptions. There are also a wide variety of issues that can produce the exact same symptoms as a vacuum leak.

If you believe you do have one, however, I would closely inspect the engine for any worn or damaged hoses and listen for any hissing sounds that may hint as to where the leak is coming from.

Finally, it may be possible that the catalytic converter is part of the issue, again though, this is less likely due to the fact that the catalytic converter and emissions system usually functions completely independently of the AC system. In order to give more insight on whether or not the catalytic converter is a part of the issue, this would require the trouble codes that came on when the check engine light came on. If you would like to get a more definitive diagnosis, a certified professional from YourMechanic can come to your car’s location to pinpoint the cause of the Check Engine Light and proceed with the proper repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: How much do you charge for the starter replacement on 2004 honda accord 2.4

In order to replace the starter on this engine the intake manifold need to be removed. It is recommended to replace intake gaskets at the same time the starter is replaced. There has been reports of the incorrect starter is...

Q: Sulfur smell while flooring 2011 V6 Mitsubishi Outlander

First thing--start buying your gas somewhere else. Sulfur is created by sulfur burning in the gas and you are getting bad gas that has sulfur in it. That's the only thing. The only other thing that can make sulfur...

Q: Changing reare valve cover on a 2010 Honda Odyssey

Unfortunately on those terrible designs, you are going to have to pull the intake manifold off to get to that. There is no other way. If you are uncomfortable with this, have a certified mechanic, such as one from YourMechanic,...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.