Novak Conversions Jeep Wrangler TJ radiator

Adventures in getting the catalyst test complete

LostHannah

New Member
Original poster
Joined
Oct 1, 2025
Messages
17
Location
California
I've been sitting with the catalyst marked as incomplete for a little over 80 miles now. what is that testing for? I have two new o2 sensors on order they seem to be reading correctly but their obviously very old.

according to the drive cycle:

Catalyst Monitor Drive Trace
Pre-Conditioning Requirements:
>> MIL must be off.
>> No DTCs present.
>> Fuel level is between 15% and 85% full.
>> ECT above 70º F.
>> Engine must have run at least 90 seconds
>> Engine between 1,350 & 1,900 rpm.
Driving Procedure :
1) Idle vehicle for five minutes (to reach closed loop operation).
2) Drive with a steady vehicle speed between 30 and 45 mph for 2 minutes.

Screenshot_20251021_180303_Torque.jpg
 
You can still pass a CA smog inspection with one incomplete readiness monitor. Sorry, not sure of the procedure to get that specific monitor ready
 
I've been sitting with the catalyst marked as incomplete for a little over 80 miles now. what is that testing for? I have two new o2 sensors on order they seem to be reading correctly but their obviously very old.

according to the drive cycle:

Catalyst Monitor Drive Trace
Pre-Conditioning Requirements:
>> MIL must be off.
>> No DTCs present.
>> Fuel level is between 15% and 85% full.
>> ECT above 70º F.
>> Engine must have run at least 90 seconds
>> Engine between 1,350 & 1,900 rpm.
Driving Procedure :
1) Idle vehicle for five minutes (to reach closed loop operation).
2) Drive with a steady vehicle speed between 30 and 45 mph for 2 minutes.

View attachment 650696

I'm not certain it's the same on the 2.5L PCM, but I know my 04 4.0L with pre-cats is still in it's warmup cycle until the coolant is hot enough to open the thermostat. It has a 195 t-stat and as I understand it runs a bit rich with advance pulled a bit to fire up the cat temps. But the target voltage is like .490 on the 2nd O2 on closed loop. The upstream at .8 is reading rich like you see at wide open throttle while the downstram is reading lean like the cat is doing it's job or there is an exhaust leak at the sensor or the flange to the exhaust downstream. Or the sensors are bad. Or you've got a bad cat, but the drop in voltage suggests not.
 
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Novak Conversions Jeep Wrangler TJ radiator