I recently purchased an 1997 nissan sentra with an misfire on # 2 cylinder and check engine light is solid and then blinks and then go from blinking to solid check engine light.it is pulling code #p0302 and p1550. I have changed plugs wires distributer cap and rotory button please help

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

The blinking check engine light indicates the engine has one or more misfire cylinders, do a fault code test to ID which one or ones is misfiring

misfire on cyl no 1 on a 01 merc grand marq

Chances are you have problems with the ignition system.
First thing to do is get the computer scanned for trouble codes to find out why the check engine light is coming on.

This is most likely a misfire. When the light blinks under acceleration it is telling you the engine is in serious need of service, which doesn't necessary mean that the engine is in serious trouble. Have your OBDII port and codes checked. Your local parts store like AUTOZONE will do this for free.

I would check that spark plug, and have that coil checked or replaced. Also check for any vacuum hose leaks in the area of the cylinder.

check engine light blinking due to engine missfire. check for spark at each cylinder and repair misfire

DO NOT DRIVE your car with the check engine light blinking! get it diagnosed and fixed ASAP.

Driving a car with a blinking check engine will most likely damage the catylist converter.

They are expensive. (to replace it can easily be more than a few hundred dolllars)
Thats on top of the original problem.

I hope this advise saves you (and others) some money, let me know if it does.
(:DK

you should stop driven the vehicle and get it repaired, The engine light flashing mean the emission problem is doing damage to your convertors.

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