Q: 2.5l Nissan sentra manual, car will run fine for about 15 minutes then will not rev while in gear, will rev when in neutral

It could be an issue in the throttle control system: throttle body, or accelerator position sensor. But there are some basic checks that need to be done before you start replacing parts. The first thing to check for in any drivability problem is air leaks. Any air that gets into the engine without being measured will lean out the system and cause problems. Look at all the rubber hoses and boots under the hood to be sure they are well connected and in good condition. If the check engine light is not on, it probably should be. Turn the key on without starting the engine, the CEL should be on. This is a bulb check feature. If the stays on after starting it means there are trouble codes stored that can help in the diagnosis. To have your car conveniently diagnosed by a professional, contact YourMechanic. They will send a technician to your home or office to check out your Sentra and let you know what it is going to take.

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