So I bought my 2004 Z last year.

After thousands of miles, catalyst, evap, and O2 sensor monitors are not ready. They were never ready since I bought the car. The PO told me the battery was just replaced, so I wasn't worried about it.

I recently reset the ecu and did a few drive cycles (300 miles worth, never above 3k rpm, always below 60 mph). The O2 sensor heater went ready in the first 5 miles but Catalyst, Evaporative System, and O2 Sensor is still not ready.
There are no CEL codes.

I noticed there are test pipes, not sure what they did with the downstream O2 sensors situation, but if its not throwing a code, it wouldnt be the problem, right?

Edit:
https://my350z.com/forum/maintenance-and-repair/480736-readiness-for-inspection-maintenance-test-and-drive-cycle.html

The part from this link says if the MIL light blinks, the the system is not ready. Mine does not blink, yet the monitors are not ready?

 

sometimes it takes longer than you think. currently having that issue with girlfriend's corolla

i think perhaps you are misunderstanding. the thread with the factory information says to turn the key to the ON position but do not turn the engine on

the service light will obviously be on, but whether it blinks after 20 seconds of being on will indicate if the monitor is ready

i assume this was to check if you didn't have an OBD2 reader device (or phones reading it off the Torque app or whatever)

obviously it's easier to check it with the phone app. if Torque says it's not ready, it's simply not ready yet

i dunno how it works where you are, but here we are allowed to have the EVAP system not ready, if the cat and O2 are ready and are not failed

having test pipes is irrelevant to your systems being not ready. i highly doubt that if the test pipes on your car were tuned to not throw codes, it would make your system not ready

this is simply my opinion because i'm fairly sure no matter where you are you can't have 3 not ready systems (that is if you need to do an emissions test regularly)

just keep driving it would be my advice

 

Without O2 sensor bungs.


With O2 sensor bungs.





Check your test pipes to see if you have ones with the 'extended bungs' for the O2 sensors(preferred). You can also have a pending code and have it not be thrown. Did you check it with an OBD2 scanner, or are you just basing the absence of a code off of the fact that you're not getting a CEL?... The pics are of test pipes with and without the O2 sensor extensions:

 

I have been checking with the torque app. No pending codes. I have a voltage reading from all O2 sensors so I'm assuming the downstream ones are there but havent checked yet.

Is it possible the o2 sensors were replaced with non oem ones or simulators thus giving bad readings so the readiness tests never start?

 

OK. If it was a incompatible generic O2 sensor the ECU would most likely throw a code. I don't know about simulators.

 

I bet it has a tune and things are turned off

 

If that is the case, I'm going to bet that he DOES NOT have the extended bungs...

 

I was just going to bring this up. If the car was tuned previously, and its very possible since it has test pipes, then the codes could be turned off in the tune which would cause the O2 monitors to never show as ready.

I would get ahold of a local Uprev tuner who can check very easily if it is tuned or not.


EDIT: It would have helped everyone in this tread if you had mentioned that the car was boosted. Get ahold of the tuner they can turn the codes back on.

 

I have thought about that too. A few months ago I found the person who tuned it and he showed me the tune had no codes turned off. He even reflashed it for me. I guess I could call him and double check the tune file again.

 

Here's what I'm looking at after a drive cycle.

 

Take it to a dealer if they hook up to the consult it will reset the tune.

 

 

The tune has no disabled codes.

I think the ecu is fine since O2 Sensor Heater goes ready just fine.

Should I just buy stock cats, reset, and do more drive cycles? At a loss here because I'm not sure what else this issue could be.

 

I have checked Mode $06 (individual tests for readiness monitors) with torque and they all show a green PASS, yet the monitors are not being set to ready.

 

I am using a UTEC, but my car readies in under 20 miles. I don't drive under 3k. Bring it right to redline. Mix highway/city.

We can have one not ready in MA to pass. (evap is always last to ready)