Q: Engine stutters then check light comes on at startup

Exhaust leaks can cause the check engine light to set. If you have an exhaust leak, it should be repaired because carbon monoxide is deadly. You can have the source of the leak identified, and repaired, by requesting an exhaust leak inspection. With regard to the poor idle, when the engine is cold, the engine coolant temperature sensor must be working properly to signal the PCM to enrich the mixture on cold start. If there is a fault with that sensor, you can experience rough idle idle as you are describing. Other possibilities are a vacuum leak, an air induction fault like a stuck idle air control valve, problems with the mass air flow sensor, defective spark plugs, a weak coil and defective oxygen sensor(s). If you desire that this problem be diagnosed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a rough idle diagnostic.

With regard to the incidents you are experiencing with the engine losing power, the cause of that can be diagnosed, and any required repairs made, if you request an engine loss of power diagnostic. To give you an initial idea, although there are many possibilities, a partial list would include oxygen sensors, fuel pump and/or filter, vacuum leaks, ignition system malfunctions, bad valve timing if the timing belt or chain is worn or skipped, blocked exhaust (e.g., catalytic convertor fails or become clogged), airflow sensor, throttle position sensor, and so forth. Whatever the cause, if you request the engine loss of power diagnostic, the certified mechanic will get this resolved. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.