Check Engine Light No Symptoms on Your Car Diagnose Code P0171 Low Fuel Trim

So you're driving your car, you recently had an oil change done, or you replaced the air filter, and now your check engine light came on. That's what we're gonna talk about in this video.

So we scan tested the vehicle before we popped the hood just to see what the code was. And it was a P0171, which is a low fuel trim issue. What you want to do is look under the hood and look for where the airbox is. The airbox on this vehicle happens to be right here and just look around the airbox. See if there's anything loose. There happens to be a mass airflow sensor right here. See if this snorkel's loose, this looks good, and everything looks good right here. I'm gonna pull this engine cover off so I can see a little bit better underneath. Slide it up. With this cover off now I can see where the throttle body is and see where this snorkel goes into the throttle body. And we found a hose right here that's actually loose. Now why this hose is loose and not where it should be, they probably took this snorkel off when replacing the air filter. Or if you did it at your house, you forgot to hook this tube back up. Slide this tube back in position. Make sure all these are tight. That should be good. We should be able to clear the code and be on our way.

The reason why we got this code and just a little simple hose being popped off like this could cause that code is because of the mass airflow sensor. The mass airflow sensor senses air going into the engine. And if any air is coming into the engine that didn't go past that sensor, that's gonna cause a code. If you had one of these low fuel trim codes and you didn't find anything near the airbox or the mass airflow sensor, definitely check any of these other hoses. Make sure none of these are loose, or you don't hear any air, you could actually start the engine and listen for a whistle in this area, that might help you find a leak.

So those are some of the things you can check out if you just recently had some work done on your car or you replaced the air filter. I hope you enjoyed this video. If you did, make sure you subscribe to our channel, ring that bell, turn on all notifications so you don't miss any of our videos.