Light went on in late winter 2011, at 88,000 miles. Onboard computer said it was the cat converter. Mechanic said this was a common problem with this body of Corolla, and turned off the light to see how far I could go. I drove another 890 miles, light came on again. I went to a second mechanic (I live in another state than the one I saw the first time), they also offered to turn off the light and then they'd fix it later.

The light stayed off for another 7,500 miles, including through an emissions inspection. Whee! But then it came back on when I was visiting my folks again and took it back to Mechanic #1. They declared it time to fix and replaced it for $775. No problems since, current mileage is 106,500.

This Corolla requires a Toyota Catalytic converter, so be prepared to pay a premium for that. Other than that, while this is an expensive problem, it wasn't a big one.

Check engine light came on around 95,000 miles. I replaced the gas cap and it went off for the next 6 months. Well it came back on around 108,000 miles. I ran the code at Autozone and they indicated it was the gas cap or the Catalytic converter. I saw many other problems such as this with this model on the internet. Of course Toyota wanted $700 for just the bolt on converter! I found a local shop A&B muffler here in Hurst. A little Mom and Pop muffler shop with a nice guy running the place. He welded on a new converter (not oem) and reset the light for $175! Drove this car for another 4 months and it also passed inspection with no problems. Of course I don't have this car anymore after trading it in for a truck. Wished I would've kept it for a daily driver!

I had a little over 80,000 miles on my 2003 Toyota Corolla LE when the check engine light came on and wouldn't turn off. I took my car to the local dealership and said the entire catalytic converter would have to be replaced. The warranty for emission control systems is 80,000 but my car had around 80,116 miles on it. I contacted Toyota to see if they would at least help me with the costs, but they said it was out of warranty and refused to pay for any of the repair bill. I later learned there was a technical service bulletin on this problem and that other drivers were having similar complications, but Toyota still refused to pay for any of the bill.

I bought from Toyota largely because of their reputation for being reliable, quality vehicles. I had hoped that Toyota would stand behind their product when it broke down and would be fair and work with me on the problem. I was very disappointed in how they handled the repair and will probably never buy another Toyota product.

I bought my Corolla from a used dealer several months ago and, because of a long commute, have put almost 9000 miles on it. I have had the oil changed every 4000 miles and recently rotated the tires. Until this past week the car had been running smoothly. The check engine light came on and I took it to my mechanic the next day. Apparently the catalytic converter had stopped functioning entirely. To replace it with another Toyota converter would have cost $1400, however, my wonderful mechanic tracked down a generic converter that works perfectly with the 2003 Corolla. It cost $790 including service charges to replace it. Yes, half the price of the Toyota part alone.

I know several other people who have Corollas of the same year and they have not had this problem, but their cars have less miles. My mechanic is Auto Master Tech in Lawrenceville, GA.