O2 Sensor
 

How do you tell if the Oxygen Sensor is going bad (or already gone)?

Well, I'm not an expert so I bought Wayne's 101 Projects book...

Project 34, p101, 02 sensor troubleshooting...

In a nutshell...

Possible symptoms:
Irregular idle during warm up
Irregular idle with warm engine
Rough acceleration
High fuel consumption
Bad/weak performance
Bad CO concentration at idle

...30k mile part... so if you don't know when it has been replaced last, just do it...

The book has alot more to say about the O2 sensor and other vitals of the motronic system.

Purchase "101 Projects" when you order your sensor. I'm a DIY'er. I bought my 84 coupe last May. I bought the book a month later. And wow, it's gold.

Cheers,

Jojo

jojo got it right. my experience with bad sensors are almost always poor mileage and rough acceleration. rough acceleration as in the car will start bucking as you try to accelerate and almost feel like it is on the verge of cutting out. i am in the O2 sensor every 30k miles camp