You people changing O2 sensors, cam sensors, etc are typically wasting money and time. You Must check your Codes and even that may only be an indicator towards the real issue: A bad sensor may only be a wire or a bad ground if several codes are showing up typically indicates bad alternator, ECM or simply a bad wire somewhere. Sensors have an OHM range and can easily be tested! Better to get a cheap ELM code reader eBay than pay $80 to someone. Every car should have this built in, in my opinion!
Without knowing what codes are showing, and to simply look for vacuum leak in that system or to clean MAF sensors when it’s running real bad, will have you delirious, and broke.
I would really invest in a good OBDii code reader, one that has ABS, SRS (TPMS now too) as these issues will put cars in limp mode. Security issues (Transponders chips in keys) are a separate problem and may cause ‘ECM Disconnected’ codes, so for some issues expensive testers may be needed like the SBB V48 (V33 is old and only good up to 2010 Models…) This tool is invaluable when Security issues prevent cars from starting, and prevent some from turning over! Anything that turns over but doesn’t starts suspect Fuel pump or Crank sensor, ECM (could be a wire on harness rubbing against the body (especially Dodge minivans etc…) Google your issue, read lots about your particular vehicle and inherent issues related to yours.
Typical things to do are start with cheapest first, MAF sensor cleaning, MAP sensor (MAP sensor will prevent car from starting. Simply unplug it; car will run rough but it will start!) crank sensor will prevent car from starting or intermittently shut down, like fuel pressure issues, Coolant temperature sensor will put car in limp mode as well as alternator issues or simply a bad battery connection or Ground wire to engine or to Body. Simple fix is to run a wire to engine and body from Negative battery post! Wires exposed to the elements such as the harness to the fuel tank/pump will deteriorate and sometimes where it goes into the body through a grommet or the harness on top of the fuel tank (some have access port under rear seat) A (corroded) poor connection at the battery causes 80% power loss for cranking engine! There are two wires connecting to starter, actually the solenoid, Big wire is to activate turn the starter but the little wire needs power to activate the solenoid which allows power to flow through a disk which gets pushed onto the Big cable from battery to the braided wire to the starter itself. Easy to connect a small wire onto the end of post of small wire and touch other end to Positive battery being careful of manual vehicles don’t run you over.
Another tip; if car won’t turn over, find starter Relay, pull it out and bridge the connection, car should turn over or Starter is bad or the connections to it or between solenoid and starter! Put car in neutral and rock it to release a starter benzoid from the flywheel, pound on a gas tank with a 2x4 to free a stuck fuel pump- Dodge recommends half tank of gas to keep fuel pump cool! Dumb!
Some brands have inherent things and with New technology like CVT, Vanos, VVT., there will be considerations towards extra failures.
You want a reliable car get a V6 Buick Allure, or Toyota Toyota Toyota!
In summarization: CVT fluid must be changed frequently, shouldnt drive in winter so slippage of wheels may occur (vibration & heat are killers of any transmission) Nissan CVT especially had high failure rate and a company that Was getting a name for itself failed miserably with this application.
Dont change parts without testing codes.
Dealer Repair Prices are crazy and perhaps Kijiji or Craig’s list mechanics offer better choices if warranties are expired. Sometimes it’s worth paying $40/hr to have issue resolved by a specialist! I don’t trust many dealers but that’s just me! (30years off & on as backyard mechanic!)
Hope this helps some, but may generate new questions to your issues.