Check engine light, code p0420, slow acceleration

2013 CHEVROLET CRUZE
116,000 MILES • 4 CYL • 2WD • AUTOMATIC
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Check engine light has stayed on. Code that is coming from it is p0420. Even after cleared. Rebuilt motor has been put in, catalytic converter has been replaced twice, and a new fuel cap has been put on. Car never overheats or makes it to the middle hot/cold line. Can be slow to accelerate when getting on the freeway sometimes, more noticeable when A/C is on. No other symptoms are noticeable.
Aug 28, 2020 at 6:24 AM
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JACOBANDNICKOLAS
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Hi,

As I believe you are aware, the code deals with a catalytic converter issue. The converter isn't performing to expectation. I have to ask if after the new catalytic convert is installed if the light stays off for any period of time because there are things that can cause the converter to fail prematurely.

Take a look at the attached pic.

Let me know.
Joe
Aug 28, 2020 at 7:33 AM
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Yes, after the most recent converter the light stayed off for about a week maybe less then returned. After that, there was a period where the light went off for another couple of days and came back again.
Aug 28, 2020 at 7:38 AM
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JACOBANDNICKOLAS
  • Experienced Mechanic
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Hi,

Based on what you described, it sounds like something is causing it to fail prematurely.

What I would suggest trying are a few different things. First, I would check fuel pressure to confirm it is within the manufacturer's specs. Here is a link that explains in general how it is done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Please let me know which 4 cylinder engine this has. It could be a 1.4L turbo or a 1.8L non-turbo. If you can get that to me, I can check the specifications and get back to you with the specifics.

_____________________________

Let me know if you have access to a live data scan tool. If you do, start the engine and check what the short term fuel trims and let me know.

Take care,
Joe
Aug 28, 2020 at 1:30 PM
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It’s a 1.4L turbo and no I do not have access to one unfortunately.
Aug 28, 2020 at 11:57 PM
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JACOBANDNICKOLAS
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I understand. What I would try is checking fuel pressure to make sure there isn't excessive pressure causing problems with the converter.

Let me know.
Joe
Aug 29, 2020 at 7:28 AM
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