Oxygen Sensor - 1998 VW Jetta

Hello there,

I currently have a 1998 VW Jetta and today the check engine came on. On my drive home from I stopped at a parts store to get the reading off the check engine and it stated that I have bad Oxygen Sensor. According to my manuel guide, it seems quite easy to replace, but was curious to see if anyone out here on Car Talk has done this before. Is it possible for an average joe like myself to replace this sensor. Does anyone know where it is located? According to the manuel, it is located some where in the exhast. Like always, thank you for your assistance!

D in AZ

It has more than one oxygen sensor and an O2 sensor code does not necessarily mean the O2 sensor is bad. This is where proper diagnosis and a manual may come in.

A vacuum leak, rich running engine, etc., etc. can set O2 codes.

If the sensor is bad and you don’t have an O2 sensor special socket (I hate them anyway) cut the wire off the old sensor and remove it with a normal socket or boxed end wrench; depending on access.
Install the new one with a boxed end wrench if possible.

Warm the engine for a few minutes aa it may ease the removal a bit. And be careful when installing a new one that you do not drop it, bang it into anything, or overtighten it.

Thank you for the reply. I have a question in regards to the location of the sensor - is it typically accessable with out having to remove additional parts (example, w/out having to remove the exhaust)? I understand that you say that the O2 sensor may not be bad, but the car has over 150K and think is would be useful to change it anyway. Any info you have regarding to where this part is located would be appreciated.

D in AZ

Repalcing an O2 sensor just because the vehicle has 150k miles would be ill advised. And if the sensor isn’t actually bad, you will not have fixed the underlying problem. In fact, you could ruin a new O2 sensor. Do not replace the O2 sensor unless you have to. As for the location, your car has more than one, maybe 4, so which one is setting the code? Also there are several different engines in 98 Jettas, which do you have?