03 Corolla--high idle while driving

Hi all,

My 03 Corolla (with 140,000 miles) has been making an odd sound sound in the last week or so of driving. It starts and runs fine, but it has a high idle sound (while driving, it’s around 2 and doesn’t really go down from there). But it also sounds like it could be a bad muffler. I turned off the AC and radio this morning to see if that made a difference, it didn’t. I know this is random info, but I was hoping someone might be able to help me. A friend recently found out she needed a new fuel pump, I’m hoping that’s not the case with my car. Thank you!


If this just suddenly started and no one has been doing any adjustments on your car, then the most likely cause is a vacuum leak. A hose could have become disconnected or simply broken. There aren’t as many vacuum hoses as there used to be so yoou might be able to find it yourself.

If you pop the hood while the engine is running, you might be able to find it by listening for a whistle.

Hi Keith, thanks for the tip. I’ll try this in the morning!