check engine light came on after starting the car, there was delay in the start for about 5 seconds and my car was sputtering and i couldnt go above 3000RPM i recently just got my spark plugs replaced, timing belt, crankshaft position sensor, oil change, but somehow thr problem still persist. does anyone know what could be the issue? i financed this car through a dealership still owe a lot of money and my dealer refuses tofix it. im stuck with no options but to fix it my self. also my mechanic had told me that my engine is burning a lot of oil you could tell because my exhaust is very black.

  • We'll need the make, year and model of the car, as well as the codes (your local car spares shop will read the codes for you for free)
    – PeteCon
    Nov 3, 2017 at 15:26
  • If the engine light is flashing, you should turn it off. It's not safe to drive when the light is flashing because further damage can occur.
    – JPhi1618
    Nov 3, 2017 at 18:30

3 Answers 3


If you see a check engine light it is an indication that the car has logged a series of faults within the ECU (engine control unit) and put itself into a safe limp mode. In limp mode a car will typically run very rich and limit it's maximum RPM and power output.

There is little point trying to guess why a car has entered limp mode. Your first action should be to plug the vehicle in to a diagnostic scanner and read the fault codes within the log. You can do this with most OBD II scanners which most decent mechanics will have access to. (They can be purchased privately too).

Once you have a copy of the fault codes which caused the check engine light to illuminate, come back here and update your question with this list and we ought to be able to assist further.

  • 1
    Sorry, had to downvote as CEL showing does NOT always mean limp home mode! I have had CEL due to broken O2 sensor, and it did definitely NOT go into limp home mode. The response and power of the engine was normal.
    – juhist
    Nov 3, 2017 at 18:32
  • 3
    I realise that, the 3000rpm limit is what suggests this vehicle is in limp mode. Nov 3, 2017 at 18:52
  • I forgot the exact code but i know it was crankshaft position sensor A that popped up when mechanic scanned it so i had crankshift position changed and the CEL still popped up with the same problem.
    – Evan Reyes
    Nov 3, 2017 at 18:59
  • 1
    The engine still isn't happy about the position sensor. Either its not plugged it correctly, the wiring going to it is damaged, or the wrong model sensor was used.
    – JPhi1618
    Nov 3, 2017 at 19:24
  • go get the exact code. Your local auto store will read them for free usually if you don't want to go back to the mechanic.
    – agentp
    Nov 3, 2017 at 20:55

ODB II scanners can be bought online for under $20, which can hook up via USB, wifi, or bluetooth to a laptop (or smartphone) running free software, (e.g. scantool, freediag, etc.).


Maybe check air filter ,gas filter, check the Throttlebody see if it's dirty. Check mass airflow sensor see if thats dirty: the he is right look for the code ::

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