Q: it idles fines in park, but cuts out in gear.

asked by on

i started my car and it idled fine but when i put it in gear it acted like it wanted to die, it was cutting out and running very rough, so I put it back in park and it quit and then I put it back in gear and it started it again but worse.

My car has 225000 miles.
My car has an automatic transmission.

It sounds like you may have a faulty MAP sensor. The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The engine computer then uses this information to adjust ignition timing and fuel enrichment. When the engine is working hard, intake vacuum drops as the throttle opens wide. The engine takes in more air, which requires more fuel to keep the air/fuel ratio in balance. When the computer reads a heavy load signal from the [MAP sensor]((https://www.yourmechanic.com/services/manifold-absolute-pressure-sensor-map-sensor-replacement), it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation (spark knock) that can damage the engine and decrease performance. This may also be caused by other closely related components such as a dirty or failing mass air-flow sensor, a faulty throttle position sensor or potentially a vacuum leak. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. it idles fines in park, but cuts out in gear.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My Car Jerks When Fully Stopped and Going 55-65 MPH

Jerking at idle is engine related, not transmission related. If the vehicle is also jerking at speed that, too, is more likely engine related. Among the potential underlying causes of this problem are vacuum leaks, EGR system malfunctions, malfunctioning oxygen...

Q: Can a loose map sensor make your car sluggish and no power

As long the MAP sensor is sealing vacuum on the intake manifold. If it is not, then it may be causing low power. You may have an incorrect part if it does not fit like the old one. Take in...

Q: Roommate getting ripped off by toyota dealership, can you provide additional info?

Hello, thank you for writing in. There are several aspects to consider in this situation. First of all, dealerships are known for insanely high labor rates, but labor should not be over $100/hr for most repairs. The technicians that work...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...