P0139: slow response O2 sensor

jblues1969

jblues1969

Member
Original poster
Joined
Dec 9, 2022
Messages
97
Location
Waxhaw, NC
Slow response O2 sensor codes are suddenly appearing. I replaced the O2 sensors last winter and got a new Wranglerfix ECM to get rid of the previous O2 Sensor Heater Circuit Malfunction codes.

Had this one pop up as I parked the jeep after a normal drive, Cleared it, and it eventually came back at startup one day.

I'm honestly tired of dealing with a new seemingly bogus O2 sensor code every time the seasons change.

One of the things I have not messed with on this jeep is the exhaust. It's still original, looks like crap, has a dent/crimp in one of the header pipes, and doesn't have an exhaust tip.
I know an exhaust leak is a possible cause of this code. Is this a good excuse to replace it end to end? Looking for advice.
Thanks!
 
O2 Sensors are NTK
I haven't. I have a code reader but it doesn't have that capability. I wouldn't know what to look for for a "slow response" code, regardless.
Stock exhaust and wiring. I've visually inspected the wiring and it looks the same as it always has. The exhaust has had a dent in one of the headers since I acquired it, but other than that there's no noticeable evidence of damage or a leak.
I haven't had a code from the O2 sensors since I replaced the ECM in September.
Engine runs smooth.
 
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