Failed emissions test o2 sensor not ready

[damageinc321]

I'm trying to figure this out cause quickly because my plates are up next week. It said that o2 sensor wasn't ready. 2018 jlur 3.6 auto 5.13 gears. A quick background of possible causes, I have a tazer installed, a cold air intake, exhaust delete, and my battery went dead a month or so ago so I pulled the fuse for aux and removed negative cable for aux battery. I have around 50k mi. I don't drive a lot of mi, quick trips so I don't know if the o2 reset since dead battery issue. I have no dash codes and it drives normal. My first thing will be to drive an hr or so this weekend to try to reset the o2 and put an obd reader on it. Anybody have any experience with this?

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[aville65]

O2 sensors and secondary air system always the last readiness monitor to set themselves. Once had a customer with a Huyndai Santa Fe, had to drive it over 1k before was ready for etest. If you have correct software can be prompted but usually must be model specific.

 

[JLfromCA]

I would guess it reset after the battery went dead, I think you’re on the right track with putting on some miles. In California you need a EO number for the cold air intake otherwise that will get flagged.

 

[m3reno]

I went through this issue after having a dead battery in my Ram...Basically, the dead battery reset all sensors required to pass emission. You have to drive quite a bit for your system to be able to store the new data. I realized it's easier for the system to reset itself and pass in the summer months vs the winter months. What they are trying to eliminate is people disconnecting their battery and resetting the trouble codes to pass inspection, so the system needs to have data stored. It took me 3 months and over 4,000 miles for me to pass!!

 

[damageinc321]

Ok re hooked up neg aux termina and put f42 fuse back in, took tazer out had jeep flashed by dealer although it didn't remove my settings as far as tire size and great ratio. Did the drive trace sensor following those steps and

It now has most sensors ok but this is what I'm still getting for codes.

 

[dsgrey]

Yes, the Wrangler is terrible. I had the steering gear tsb done 2 years ago where the dealer disconnected my battery and failed inspection 2 weeks later on 3 not ready codes. Drove a few hundred miles over the next few weeks and still had one not ready which is okay in my state for inspection. I recall some crazy scenario where you're suppose to drive between something like 30-45mph without stopping for 5 miles immediately after starting which is impossible. 12 months later I noticed that code was in ready state just before I got inspected.

 

[maestro5531]

Per EPA 2001 and newer vehicles can have 1 monitor not ready and should still pass. You can even have a pending engine code and still pass. Google OBD emmision cycle and it will tell you how to get all monitor ready. You gor to have fuel level between 1/4 and 3/4 for the evap, If I recall correctly, drive 5 minutes at 55mph, then coast to stop, repeat 3 times.

Few month ago my friend had a code for catalyst below efficiency, I reset the light, went for a OBD drive cycle with my scan tool, p0420 was pending but I completed readiness monitors and passed the emmision test for him.

 

[damageinc321]

Update, small battery changed still wasn't passing, PCM replaced and it finally passed. Under extended warranty only cost me$100 deductible.

 

[Melchior]

This normal. This isn’t about replacing the battery. It’s about “DRIVE CYCLES”. The same thing happens to ALL brand new cars. If you go buy a car right now with under a thousand miles under the ODO, you won’t pass smog/inspection.

The ecu/o2 monitoring system needs a few “drive cycles” to be completed. Happened with all the brand new cars I bought from out of state that needed to be smogged/inspected in CA. I needed to drive around 1000K before it was “ready”. This happens everytime you disconnect the battery. The ecu has to “learn” again. Just keep driving it as much as possible or check out what the requirements for a Stellantis “drive cycle” is. Every manufacturer is different. My Chevy needed X number of stops/idles, X number of non-stop cruising speeds and etc.

I never could do the proper drive cycles, so I just ended up driving normally (combined city and highway) as much as I can before all the parameters were met.

 

[Big_Al]

Hilariously... the cure to activating the sensors that monitor your vehicle's emissions is to drive around more and put more emissions into the atmosphere...

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