A friend of mine has a Hyundai Elantra (don’t know the year) with about 50,000 miles on it. His Check Engine light came on, freaked him out, and within 3 miles he had it in a big chain shop for repairs. They told him it was the O2 sensor and that it’s malfunction had also caused another mess somewhere (I have no details), which added over $200 to the total bill.
My reaction was: if you stopped within 3 miles, how could a bad O2 sensor possibly cause other problems? I don’t know anything about Hyundais, so maybe this is reasonable? I think he got hosed.
I agree with you. When an O2 sensor fails, you replace it and you are done. There might be a problem with the catalytic converter if you drove with a bad sensor for a few thousand miles. 3 miles should not be a big deal.
Yet another good reason to avoid chain shops.
Does your friend realize that his Elantra is covered by the Hyundai 5 year/60,000 mile bumber to bumper warranty?
And that if-instead of panicking-he had taken it to the dealer the repair would most likely have been covered free of charge?