Codes P2239 and P2238, I need help with diagnosis?

Tiny
JRP89
  • MEMBER
  • 2021 NISSAN SENTRA
  • 2WD
  • AUTOMATIC
  • 48,000 MILES
My vehicle has an on and off check engine light for a small amount of. I've noticed one time it kind of rattled when idled at a light and occasionally when driving it will seem to briefly struggle to accelerate. I took it to diagnostic and codes came back x3 for p2239 and x3 p2238. The person who helped with the diagnostic said probably spark plugs, but after googling said codes, it deals with voltage and o2 sensors. Is it possible a faulty spark plug or plugs could still cause this or am I looking at my o2 sensor most likely to replace?
Thursday, September 26th, 2024 AT 1:58 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

You are correct about the codes. Both deal with the upstream oxygen sensor. The sensor may be faulty, a wiring or connector issue, or a few other things.

Since you heard a rattling sound, that could be related to the catalytic converter as well. If the internal components are no longer attached, they can rattle and in the correct position, restrict air flow. That can cause a power loss and skewed o2 sensor readings.

Take a rubber mallet and tap on the exhaust to see if you can recreate the sound. If you can't check close to the front portion of the exhaust to see if that is where the sound comes from.

Next, because this vehicle is only a couple years old, please keep in mind the oxygen sensors and catalytic converter are both covered under the federal emissions warranty. Many components have an 8 year or 80K mile warranty. You should contact a dealership to see what they tell you. It may be a repair under warranty. (See pic below)

Also, at 48K miles, the spark plugs are not in need of replacement.

Let me know your thoughts.

Joe

See pic below.
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Thursday, September 26th, 2024 AT 3:35 PM
Tiny
JRP89
  • MEMBER
  • 4 POSTS
I'll have to get in touch with a dealership when available. It hasn't done the rumbling since. Just that one time and it was early in the morning too, so I could have just been overreacting to something minor not being awake. It was more like a feeling than a sound. Like, it felt more shaky for a split second.

It was fine one minute and as after I put some gas in my tank yesterday, caped it, and started going, I saw it on.

I'm going to have it looked at soon, but I was in hopes I could get a hold idea of what I'd be looking at replacing finance wise or if it's easily doable at home.

I know as I currently write this, the check engine light is now off again.
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Thursday, September 26th, 2024 AT 3:59 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

If anything changes, let me know and I'll try my best to help. Just remember, many of the emission related components are covered for an extended period of time.

Take care,

Joe
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Thursday, September 26th, 2024 AT 6:03 PM

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