I know this topic gets covered quite a bit but....



Last night I was highway driving at about 70mph. I was not pushing the car at all. When I exited the highway the car let out a large puff of white smoke. Then it would puff the smoke after each gear change.



I stopped at a restaurant to eat and it did it again after I ate but then it did not do it after highway driving it home.



It did not do it this morning on the way to my office either. the rebuild has 5000 miles on it of not hard driving at all. I baby this car...always have.



I am upset about it right now and need any thoughts on what might be happening. Just to add the car is getting pretty lousy gas mileage, about 12mpg.



Thanks.



Greg

 

12mpg is way low, are you driving over 3800rpms a lot?



mike

 

No. I am very easy with this car. In fact 3500-4000 is where I shift usually all the time. I was getting 18 in the city and about 23-24 on highway just a couple of months ago. Since then the only changes I have made are new plug wires (I double checked to make sure they were on correctly), my new Cat-back. That is it. The engine still runs very strong and does not hesitate or anything. Oh, yeah, the air conditioner was recharged.



Greg

 

weird, maybe your o2 sensor died?



mike

 

That is a distinct possibility. It is the original O2 sensor from 1987. The engine was rebuilt and the original sensor was put back on. Are there any other ones that work besides the Mazda one which I know is very expensive and also, how can you test to see if it is working or not?



Thanks,



Greg

 

you can put a voltmeter on it and drive around. any o2 will work. if you can find one the ntk is better than the bosch (ntk is the mazda sensor)



mike

 

At 5000 miles, your motor is broken in. You need to start redlining it.