Sponsored

'21 JLR Failed NYS Inspection / Emissions Test

Rubi-Con

Member
First Name
Mike
Joined
Oct 29, 2025
Threads
2
Messages
8
Reaction score
10
Location
Rockaway Beach, NY
Vehicle(s)
2021 JLR
Greetings. New Poster here.

I was shocked and super stressed last week after my '21 JLR (manual) failed it's annual NYS Safety Inspection for emissions at my Jeep dealership on Long Island. It generated a report stating that the "On Board Computer System (OBD) was not ready to make a determination of the condition of the pollution control system on the vehicle." More specifically it stated that the O2 Monitor and the EGR Monitor were not ready.

My Jeep is exactly five years old and has only 29,000 miles on it.

Back in July I had the auxiliary battery replaced that runs the annoying ESS Start Stop. I had a warning light on the dash about it and the dealership said it was due to that battery being dead. So now the guys at the dealership told me that when they changed the battery it cleared the DTCs on the computer and I just had to drive more. Meanwhile, that was months ago and I had put about 1000 miles on since then (local and highway).
They told me to drive 50 miles at 60 mph steady and come back. Skeptically I did that, came back, and it failed again! I left unhappy to say the least. I've never had a car fail inspection before and I've had some clunkers over the years. Now I was stuck in some emissions test limbo with an inspection sticker expiring in 2 days.

Kudos to the Jeepers on this forum because I was able to find previous posts regarding similar issues that saved my butt!

Unbenownst to me you need to complete a series of Drive Cycles so that the monitors in the OBD sytem reset and become "ready".

This is what I did:
First i bought a cheap OBD II scanner / reader on Amazon for $19 which arrived in a day.

Then I performed this Drive Cycle to clear the EGR monitor:
1. Cold Start
2. Idle (parked) for 5 minutes
3. Drive at a steady speed between 40-60 mph for 2 minutes
4. Coast to under 20 mph before applying brake and pull over.
5. Park & Idle for 3 minutes.

A few days later I performed this Drive Cycle to clear the O2 monitor:
1. Cold Start
2. Idle (parked) for 5 minutes.
3. Drive to 35 mph and come to a complete stop.
4. Get on a highway and drive at 55 mph for 3 minutes shifting into 6th gear (manual)
5. Decelerate to 20 mph (no braking, no downshifting)
6. Accelerate to 55 mph for 5 minutes. (I did shift into 3rd gear and back up to 6th for this step)
7. Decelerate down to 20 mph (no braking, no downshifting)
8. Park & Idle for 3 minutes.
9. Turn off engine for 3 minutes.

Shockingly, these both worked for me the first time. I plugged in my OBD II reader and both monitors were showing as ready. Back to the dealership and it passed Inspection! What a relief!

Again, I want to thank those on this forum because I would have not figured this out.
The dealership was not this specific and basically just told me to keep driving.

The only thing in the vehicle manual that refers to this is on page 133. "If your OBD II system is not ready, you should see an authorized dealer or repair facility. If your vehicle was recently serviced or had a battery failure or replacement, you may need to do nothing more than drive your vehicle as you normally would in order for your OBD II system to update."

Not sure if the manual trasmissions are more finicky with this. I rarely use 6th gear. I wonder if that had something to do with the O2 sensor not resetting this whole time.

Anyway wanted to post this in case someone else out there comes across this problem.

Lessons learned:
1. Don't wait until the very end of the month that the Inspection sticker is expiring to have re-inspected
2. Don't disconnect any batteries as the time nears for an annual inspection / emissions test / smog test, etc.

Happy Trails! ✌
Sponsored

 

Tr4ckD4ys

Well-Known Member
Joined
Dec 4, 2022
Threads
29
Messages
951
Reaction score
1,878
Location
NY
Vehicle(s)
2025 Jeep Wrangler Rubicon Xtreme 35-inch 2-door, '41 Green
Build Thread
Link
Occupation
Tech
Hello fellow long islander
 

jharp

Well-Known Member
First Name
Justin
Joined
Oct 15, 2025
Threads
1
Messages
171
Reaction score
389
Location
Kitsap County WA
Vehicle(s)
2025 JLUR, 2024 JT, 2025 R1S
Many of the "onboard diagnostic/functional performance" not-ready issues are related to the computer needing many drive cycles, and in some cases thousands of miles before they set a "status normal" code. Diesel systems are even more finicky - I found on GM Duramax trucks you actually can't pass an emissions/smog test in the first 5000 miles because of these codes.

Thanks for sharing your solution to this!
 

Bill_BCNtoNY

Well-Known Member
First Name
Bill
Joined
Jul 17, 2022
Threads
14
Messages
1,327
Reaction score
2,109
Location
NY
Vehicle(s)
Ocean Blue JLU Sahara 3.6
Occupation
Advisor to Boutique Consulting Firms and Solo Practitioners
Had a similar situation with mine here in Westchester - the computer kept saying the Jeep wasn’t ready. One of my local mechanics was nice to let me keep driving by every other day or so to check what mood the computer was that day, and one day voila! He kept the car for 30-45mins and it passed with flying colors.

The way I think about the issue with the computer is that there a bunch of processes that can trigger a reset of the emissions “tachometer”, and to be able to do the inspection test you need the car to tell the inspection software that it’s ready, as in “there haven’t any weird events of late and I’ve been running normally”)
 

Sponsored

azjl#3

Well-Known Member
First Name
Scott
Joined
Sep 24, 2022
Threads
17
Messages
3,071
Reaction score
3,720
Location
North AZ
Vehicle(s)
2024 silver zenith or atomic silver. JLUR Extreme Recon-ish
Occupation
retired, grumpy, yet, friendly

Bill_BCNtoNY

Well-Known Member
First Name
Bill
Joined
Jul 17, 2022
Threads
14
Messages
1,327
Reaction score
2,109
Location
NY
Vehicle(s)
Ocean Blue JLU Sahara 3.6
Occupation
Advisor to Boutique Consulting Firms and Solo Practitioners
WTH is up with GW bridge, I about snapped my blue ox off towing my jeep
IMHO the GW just needs to be avoided all together. Totally worth driving a bit further north and cross via the Tappan Zee.
 

Tr4ckD4ys

Well-Known Member
Joined
Dec 4, 2022
Threads
29
Messages
951
Reaction score
1,878
Location
NY
Vehicle(s)
2025 Jeep Wrangler Rubicon Xtreme 35-inch 2-door, '41 Green
Build Thread
Link
Occupation
Tech
WTH is up with GW bridge, I about snapped my blue ox off towing my jeep
IMHO the GW just needs to be avoided all together. Totally worth driving a bit further north and cross via the Tappan Zee.
Yeah…. There are only very rare times of day one can take that bridge without risking a mental breakdown. Unfortunately though it leads straight to this beautiful little road called “Henry Hudson Drive” that is never really busy and in my opinion offers the most stunning view of the upper and middle manhattan island anyone can get.
 

azjl#3

Well-Known Member
First Name
Scott
Joined
Sep 24, 2022
Threads
17
Messages
3,071
Reaction score
3,720
Location
North AZ
Vehicle(s)
2024 silver zenith or atomic silver. JLUR Extreme Recon-ish
Occupation
retired, grumpy, yet, friendly
We enjoyed the drive, traffic not bad midday, but the buckling on that thing, wow worse than anything on Alcan hiway


Annnnd hoping epa allows retrofit delete kits on diesel
Sponsored

 
Last edited:
 







Top