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: Head Gasket replacement

Hi there: In general, the tips you've listed are very important to remember, but you are missing on very critical step - purchase a 2001 Honda Accord service repair manual and follow their specific instructions exactly. Also, if you're completing...

Q: How do I find out with my 2008 Honda Accord Sedan 4cyl engine is California or Federal regulated for emissions?

All cars have an emissions sticker on the core support, (radiator bracket), or on the under side of the hood. You will need to read the sticker and look for it to say California. If it doesn't, it will be...

Q: Noise coming from area of belts. I think it may be the ac compressor or compressor clutch

The car is safe to drive, but you probably won't have air conditioning. The main thing you want to consider is the A/C belt also driving the alternator. If the compressor clutch bearing locks up, it will break the belt...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...