SRL

Pulling my hair out right now with this issue on my 2004 GT3. Car always passed smog with flying colors before this new ******* stupid OBD ll monitor test! What a joke changing the rules on a car that's 12 years old!! I've done the drive cycles, checked the monitors with my durametric, and STILL can't get the catalyst monitor ready. NO CEL, no running issues, no nothing! Someone help before I set this thing on fire on the steps of the capital building!!!

Mike in CO

Do you have O2 sensor extenders? That solved the problem for me.

4porsh

I've recently been there. I put hundreds of miles on car doing the cycle's perfectly. Could not clear catalyst monitor and secondary air to clear. I then put stock exhaust on and 15 mins into the drive cycle the catalyst monitor cleared for me. (drove around with durametric in the obd2 port) Then drove to indy Porsche garage that has the official Porsche readier/scanner and had them put the car in a ready state which cleared secondary air. I immediately went to get smog and passed.
Next time I will find/pay a place to "make it" pass, even with race exhaust on.
Good luck.

996TWINS

I pretty much drive the car on weekends and took almost a year to get this cleared up. Kept the paperwork in the car showing the registration fees were paid, incase I got pulled over.

Did the drive cycles above without success either, checking with a scanner every time after a drive.

What worked for me was to start up the car and let it idle for 20 minutes after sitting over night, which I did once. Then driving at a constant speed on the street for a bit and on the freeway a few times during the week and my "normal driving". Not sure about exceeding 3000RPM came into play or not.

Got the "Monitors Ready" in less than a week.

Hope this helps.

stuttgart1

Find a shop that know what they are doing and force it to ready state, it should take no more than 1hr if they charge you by labor.

Mike in CO

My shop knows what they are doing, but they were unable to "force" the ready state. They tried the PIWIS "Short Test" which is typically how shops "force" the ready state, but it wouldn't complete.

In my situation my aftermarket cats weren't working efficiently enough to allow the ready state, even though they were working well enough that a CEL wasn't being triggered. It was kind of an in-between state.

I chose to install O2 sensor extenders, after which the Short Test ran successfully and the computer immediately showed ready. I haven't had a problem since.

Mike

Spyerx

FWIW, at least on my997 the short test would not set 2 of the 7 or so indicators to ready. those had to complete over time.

SRL

Car is dead stock.

SRL

See now that's the bitch of it and why it's so unfair to change the rules on this old technology. The car either has a CEL on, or it doesn't. And if it doesn't, then TEST the damn thing!!! At that point if it fails I'll at least have a path forward.

Forcing people to drive around aimlessly on expired tags trying to get "monitors to set" is ABSOLUTE BS.

SRL

Mike, I honestly had no idea they existed. I looked them up and find it hilarious that someone thought of a small threaded pipe to move the downstream O2 sensors further from the exhaust flow, thereby fooling the computer into thinking the cats were more effective. Genius.....and a pretty severe indictment of the technology we're dealing with here.....

My question is.....what is this "nether world" we're in where the catalyst is potentially effective enough to NOT fire a CEL, but NOT effective enough to allow the catalyst monitor to reset? I mean, that is the real joke here.....talk about a recipe for having to throw parts at a car and pray they fix it.....pretty bad considering the cost of our O2 sensors and catalysts!

Mike in CO

Yep.

wilfred

Don't know where you are but if possible, take it to Walter in Riverside. I had a dead battery the morning i was going to get a smog check few years ago and they told me I needed something flash/reset before hand and it was $100-200 i think. So that and a new battery was an expensive smog check but i rather pay someone that knows what they are doing.

bb911-02

Stuttgart1 - Thanks for the post stating how to drive to turn it on (get to ready state). My catalytic converter would not turn on either. My mechanic pointed me to you post.

Skeptically I tried it, and it worked!

stuttgart1

Glad it work out for you

yaknart33

The fuel level also needs to be between one half and three quarters full.This will cause some monitors to fail.The system uses fuel vapors to test several monitors so if the fuel is to low or high it will not be able to test or pass some monitors.