multiple codes which include, P0324, P0326, P0327, P0328, P0172, P0501, P0A4A, P0C47, P07E8?

2014 BUICK ENCORE
224,000 MILES • 1.4L • TURBO • AUTOMATIC • ELECTRIC
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BJOHN13
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I recently did a engine swap on my buick encore. before putting the motor in i did a code reading on it to ensure the motor was in good condition which it was. after the install my buick started and ran but its running rough. idle is rough, belt is squealing, and there is some hesistation when accelerating along with a strong smell of gas. I hooked up the code reader to find multiple codes which include, P0324, P0326, P0327, P0328, P0172, P0501, P0A4A, P0C47, P07E8. i started with replacing the knock sensor and deleted the codes and reran the code reader with similar but different results. now the codes include P0324, P0326, P0328, P07E8, P0A4A, and P0A47. I did some research into them, with the knock sensor being replaced im thinking its a connection issue rather then the sensor itself. the other codes kind of give me the thought of poor communication or connections as well. It seems the ECM, PCM, and possibly the TCM may not be signaling god or one is faulty. Im looking for input and second thoughts. I also dont want to go buy parts without finding the most likely issue but not sure how or where to start. I also must add the battery light is on but battery tested good and the alternator is showing a charge at 13-14 volts.
May 6, 2026 at 7:02 PM
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STRAILER
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Yep, the first thing I would check is the main engine wiring harness grounds to the engine, it sounds like one of them is off. If the grounds are all good, clear the codes and then turn the key on and without cranking the engine over run the codes again these will be the main hard codes we start with. Here are the ground locations so you can check them out. Check out the images (below). Let us know how it goes
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May 7, 2026 at 4:30 PM
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BJOHN13
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so i noticed the knock sensor and alternator wiring was backwards. That was fixed and it ran better but still a little rough on start up going into idle. and has the smell of gas still. i cleared the codes yet again and redid the scan, which yet again came up with knock sensor codes P0324, P0326, and P0328. along with P0172 (system too rich bank 1) and odd enough i had a new code that showed but then disappeared when i cycled through the codes again to write them down. it was C342D manufacturer control. It has not returned on the list. is it possible because the wiring was mixed up with the alternator that the knock sensor was compromised? I have yet to check that engine wire.
May 7, 2026 at 9:52 PM
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STRAILER
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The knock sensor and alternator should be okay, does the alternator charge when the engine is running? Also, can you upload a short video of the engine idling so I can see it? The codes and the way the engine is running can still be a bad ground let me know after you check the wiring.
May 9, 2026 at 4:18 PM
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BJOHN13
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i can take a video. i ended up getting a code for the coolant temp sensor so i replaced that and now the only code showing is the P0172. I had the battery disconnected for about an hour yesterday so the knock sensor codes are now gone and have not returned, they showed as a permanent code on another code reader. So i gave that a try. the battery and alternator are working good now and charging normally. im going to try replacing the valve covers this afternoon and check for any leaks of any sort and see if the MAF is dirty or faulty. it seemed a bit wiggly when i moved it yesterday. i will take that video when i go out to work on it soon.
May 9, 2026 at 6:33 PM
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STRAILER
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That would be great! Glad we got the one problem handled. Now lets get the next problem handled.

Code P0172, the computer is seeing the engine running too rich on Bank 1. So the first thing to do is check for a vacuum leak.

Also, I would clean the MAF sensor these vides should help.

https://www.youtube.com/watch?v=LRKWV4Are5c

and this guide can show you howe to clean the MAF

https://www.2carpros.com/articles/throttle-actuator-service/

Please go over these guides and get back to us.



May 10, 2026 at 5:13 PM
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BJOHN13
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Complication happened i blew a coolant line. Water outlet where the pin is coolant is pouring out. So can't start the car until I get that installed. But I have replaced air fuel ratio sensor, valve cover, cleaned the MAF sensor, attempted to test the MAP sensor but can't make connection to test. Replaced all spark plugs, and did a ohms reading on the injectors and all readings are within normal good range. And I did the blow test on the purge valve which seemed good. However im attaching some photos and wondering if this is missing a connection of any kind and does the intake look normal? And i noticed there is a missing clamp on the air intake that attached to the airbox.
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May 13, 2026 at 7:55 PM
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BJOHN13
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I just got off the phone with the owner of the car i used the motor from. And he informed me that he put bigger injectors in the motor. Im thinking that is the cause of the p0172 code. I have the original injectors he had, in the cars glove box. Checked the ohms and they are good. Think its worth putting the normal sized ones back in? Or should I buy new ones?
May 13, 2026 at 8:11 PM
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STRAILER
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Yep, I don't like after market fuel injectors and testing them using the ohms is only one side of the injector, mechanically then can be bad and not spray correctly. Don't worry about the intake tube to the air filter that will not cause a problem. Here is a guide if you want to test the mechanical side of the injector.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector/

Please let me know what happens.
May 14, 2026 at 3:27 PM
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BJOHN13
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Got the water outlet and original injectors out in today. The p0172 code is STILL there. Also have the p0118 code again for the temperature sensor. Says that could be from air in the system though. So I will try bleeding it again tomorrow. As far as this p0172 code I am so stumped at this point. But it did start and idle better.
May 16, 2026 at 4:28 AM
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STRAILER
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When it does start and run how is the engine power? IF it is low you might have a clogged catalytic converter. Here is a guide to help us see why the engine is running rich

https://www.2carpros.com/articles/why-an-automotive-engine-will-run-rich/

Please go over this guide and get back to me.

May 17, 2026 at 3:32 PM
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BJOHN13
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I was looking over all the harnesses again and sensors and somehow the p0172 code has cleared. But the p0118 code is still there, I have a brand new coolant temperature sensor in and replaced the one on the radiator as well. The sensor itself seems a little loose in its hole as I can wiggle it slightly. The temp gauge also fluctuates when its running, I noticed when I massage the radiator hose it causes the gauge to go up to where it should be but shortly after it fluctuates again. But its not stuck on cold any longer.
May 17, 2026 at 3:45 PM
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STRAILER
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We are getting closer than, the sensor is not suppose to be loose so it sounds like it is bad. This is why the gauge fluctuates.
May 17, 2026 at 4:20 PM