I have an '87 nissan sentra and the sensor light is on , what should I do? The car is also idled too high how do I fix that and it also burns a lot of gas?

I am not very good at idle problems. Sometimes when a car is set at a high idle, it is because someone put it that way because it dies at low idle, which usually means there is another issue causing it to die, like a stuck open EGR valve or something...

On the sensor light, which sensor is it? Or what does the light say? All cars have different sensors and lights. On my truck, the O2 (oxygen) sensor light came on after 90,000 miles because the oxygen sensor is supposed to be changed at 90K miles.
More info...

It just says sensor. I have another problem now. I was driving the other day and it cut off on me and I had to have it pulled home. Before it did this some times when I tried to crank it would be slow starting.

Did it die at idle or while driving freeway speed?

I think I was doing about 15-20 mph. I was driving in the country and it just cut off( I can't remember if it was shaking a little or not). I tried to recrank it to no avail.

This may be easier for a mechanic to diagnose from afar. However, I am not a mechanic, just someone who has worked on his own cars for 16 yrs.

If you are pretty good with cars, you can get a repair manual and go through the troubleshooting section under car won't start.

Or, you can get a friend to look at it who knows about cars. If you are not really very mechanically inclined, take it to a shop.

If the trouble started when the sensor light 1st appeared, it is a good bet it is related to that. But there are lots of sensors connected to different components! When a car won't start, I always try to test for the basics 1st:

A car needs Fuel, Compression, and Spark to run. If the battery seems low, Jump the car with another car to make sure you are getting juice.
1. Crank it over several times pumping gas pedal, remove a spark plug or two - is it wet with gas? If so good, you have fuel.
2. Get a spark plug Tester (cheap at auto parts store) and test the spark by connecting it to the coil wire, tester should come with directions. Is it a good strong blue spark? If so, that is good.

Beyond these basic checks, you can check compression, and many other things listed in your repair manual specific to that car. Also, Do you change your own oil? If you do, was there any milky brown looking oil last time you changed it?

Look in the radiator see if any oil is mixed in with the coolant. This can signal a blown head gasket. A compression test can reveal this also.

Has the car run Hot at any time recently?

If this all seems too complicated, let me know. Do you have a repair manual for your car?

As for your question about burning a lot of gas: How many miles does the car have? When was the last time it had a tune up (plugs, wires, air filter, fuel filter)? Is it suddenly burning a lot of gas or has it always?