Engine hesitates at high RPM, 2005 3.7L

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Tarkhan

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Hello,

The engine works just fine at low RPM but when it accelerates and reaches higher RPM, it starts to hesitate. The computer reads P0157 and P0158. any idea what can it be?

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xc_hide_links_from_guests_guests_error_hide_media
This is what happens (notice the sound)
 
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03GoingStrong

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If the fuel air mixture isn't right, the engine will not run properly. First, I'd check for frayed and worn wiring such as the guy in the video talks about the O2 sensor wiring near the driveline, but follow the wiring and check connectors too. Rule out the simple stuff first.

EDIT: Check these links for some ideas ... https://repairpal.com/obd-ii-code-p0157 ... https://repairpal.com/obd-ii-code-p0158
 
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Tarkhan

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xc_hide_links_from_guests_guests_error_hide_media
This is what happens (notice the sound)
 

LibertyTC

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P0157 2/2 O2 Sensor Shorted to Ground
P0158 2/2 O2 Sensor Shorted to Voltage
Sound like wiring issue or bad sensor.
Only use NGK/NTK 02 sensors for the replacements.
 

Tarkhan

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P0157 2/2 O2 Sensor Shorted to Ground
P0158 2/2 O2 Sensor Shorted to Voltage
Sound like wiring issue or bad sensor.
Only use NGK/NTK 02 sensors for the replacements.
Thank you. Can that be the reason why I'm having this hesitation?
 

03GoingStrong

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Normal if you are parked and not moving.

it is the engine computer keeping you from doing stupid teen-age guy stuff to see how high you can rev the engine with no load.

see this -

https://www.jeepkj.com/threads/rev-limiter.27309/
So very true. I'd forgotten about that. Don't often redline the engine LOL and was so focused on the codes, didn't pay attention to detail in the video. Wonder if the codes are a result of redline or preexisted? Clear the codes and see if they come back I guess ... and don't redline the Jeep.
 

Tarkhan

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Thank you so much guys, I didn't know that tbh (that's my first Jeep). I will try to clear the codes first before checking the sensor.
 

DadOSix

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Redline won’t set codes.

i’ve got 2 - an 04 and 06

both 3.7, both auto.

from libertytc’s post, sounds like the wire has rubbed thru.

good luck!
 
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