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Q: P0171 Code comes on, Car is sputtering in the morning.

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For a little over a month, P0171 (System to Lean) code comes up. My brother has cleaned the throttle and the MAF. It then worked fine for a few weeks, then the code came up again and the sputtering started. He took it to O'Reilys Auto Parts. They had said since you removed the trottle and put it back in, it would need to retrain itself. He then removed it again and cleaned out other parts in the car. Just the other day, my car started sputtering again in the morning. It runs fine the rest of the day. Also, when I was out of town the other day, my car sat for about 4 days with a low tank of gas. When we were traveling on the highway, my reduced power engine light came on. Once I filled up with gas it was fine. i am just trying to see what could be the problem. Do I need a new O2 sensor, a change of the manifold gasket, fuel injector cleaning... Not sure. The car is good to drive, but would like to fix this problem.

My car has 138000 miles.
My car has an automatic transmission.

There are a couple technical bulletins for your car addressing an issue where the injector wires are not connecting to each injector correctly. It’s a possible that they are crossed in your case. The other bulletin says to clean the injectors. If both of these check out then you should look for a vacuum leak in the intake when the engine is cold. It may leak more cold than hot which can cause the lean code. I’d suggest getting the vehicle looked at by a certified mechanic who can perform these checks and diagnose your Check Engine Light firsthand. An accurate repair can then be followed through once the problem has been pinpointed.

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