My 2002 nissan sentra check engine light flashes

it can be a number of things ---have vehicle scanned a blinking check engine usually means a misfire with 1 or more cylinders most auto stores offer this service for free --with misfire can be plugs -coils-wires-bad gas --throttle body fault--fuel delivery problem etc

CEL or (check engine light) means there is a serious engine problem AND YOU SHOULD NOT DRIVE IT.. You can damage the engine.

check that your spark plug wires are all secured tight. the far right cylinder is giving you the issue, cylinder #4. Is the engine light flashing while the car is running? if it isnt flashing, then its a past code and isnt misfiring anymore. if the engine light is flashing, you either have a bad plug wire, or a bad ignition coil/distributor.

I assume the car was running before you replaced the computer. If you still have the old computer try it on. This will help you determine if the problem isn't in the new computer. If you can't test as above, check for power to the distributor. If no power then check the circuit from the computer to the distributor (first the fuses that are marked "Engine Control" then the wires at the connector on both ends). If the circuit is OK then the computer is probably faulty.
If you get power then check the coil pack or the distributor. I don't have the wiring diagram for the 2002 Sentra but usually power to the pump is controlled by the distributor.Please feel free to let me know if I can help you more.

Take your car to a local parts store, they will read the engine code for you for free. They will also offer possible actions  fix it and parts it will take. Be careful out there.  

My 2000 sentra did the same thing it took me several monthes to figure it out the solution was is simple. Clean the battery conections and the problem will be solved.

Sounds like it could be faulty fuel injectors. (unless of course, it's carburated, then it'd be a poorly adjusted float)

Finding out what the code number is, is the first step.

You can find this easily by watching the blinking yellow check engine light and counting the number of flashes for each of the numbers in the 4 digit fault code.

To do this without a code reader; sit in the car and turn the ignition on (do not start the car) and after 3 seconds push the accelerator pedal all the way down to the floor and release fully (pull your floor mat out from under the gas pedal). After the 3 seconds, do this 5 times quickly, in less than 5 seconds. Then hold the accelerator pedal down for exactly 7 seconds and release it fully. Then within 10 seconds, the yellow check engine light will begin to blink.

The numbers of blinks will go from 1 to 10. A 10 will represent a "0".

For example; 0303 would be 1st number is 10 flashes, short pause then 3 flashes, short pause then 10 flashes, short pause and 3 flashes. It will repeat this again if there is only one fault code. There could be other fault codes and you would count those in the same way.

The 0303 code means that you have a cylinder misfire in the #3 cylinder. This could be a fouled plug, poor connection between the plug and the coil or something else.

To erase the code hold the gas pedal down while the yellow light is blinking for about 15 seconds then turn off the ingnition. Code will now be reset and light will go out.

If for some reason you do not get the yellow light to start blinking, tturn off the ignition and try it again. You may wish to get a watch with a second hand as the time is critical as to the seconds between steps.

After you find out what codes you have, send back an email and we can document the actual codes and the problems you are having.

Bob - 2003 Nissan Sentra SE-R spec V

Blown fuse, or could be the dimmer switch. Check fuses first.

have you ever done trans flush??/powerflush??it will flush EVERYTHING. dump and fill only get's so much. how is the fluid in the trans??is the check engine light on??