Hyundai Repair: check Engine light,air bag light, dot 4 brake fluid, vacuum line

Question
We have a 2001 Sonata 4cyl and quite some time ago the chk engine light came on and it was I believe an 02 sensor.If I remember correctly and there were 2.I replaced both and each time after a reset it lasted about 65kms.Then came the airbag light.But the car does not run any different,just a pain.Could it be a vacumm line? Also is it Dot 4 brake fluid?

Answer
Hi, Kevin.  The problem with the check engine lamp could indeed be a vacuum line or any of a huge number of other issues.  In fact, there's too much to check without knowing the trouble code.  If you can report the trouble code to me, I can advise you how to proceed.  AutoZone and AAMCO have advertised they'll check diagnostic trouble codes for no charge.

The air bag lamp is probably a different and unrelated issue.  You'll need to take the car to a dealer or shop with a scan tool capable of interrogating the air bag system to find out the nature of the problem.  The only fault I've seen that will cause a check engine lamp and an air bag lamp is a faulty alternator.  Most frequently, when both lamps are on, there are two separate problems.

You can use DOT 3 or DOT 4 brake fluid.  The vehicle was originally equipped with DOT 3 fluid.