I passed emissions but still had a not ready flag raised on the report. It was for 02 heater.

I am trying to prep the car for when i get the bigger cam so that I can pull a fast one on OBD2 via programming out a few things. The law states that you can have 2 not ready flags raised and still pass with 2000 models and under.

So the question is how do I track this down, since it is not throwing a SES code?

Also how could the O2 fail on the heating end, yet still sense exhaust gases properly?

I dont want to use one of my not ready areas up on something like this.

 

Your inspection test must look at history codes set in the PCM. Since ALL O2 faults in OBDII set a SES light.

The PCM will run the heater test only on a cold start and only once per ignition cycle. The test consists of the PCM monitoring the bias voltage of the feedback signal. It does NOT monitor the heater circuit. It looks at the amount of time it took for the O2 to start fluctuating away from bias voltage. If this time is too long, it sets the SES and a DTC.

If you put simulators on the back 2 O2s, that would be 2 less problems to have to contend with. Then you only need focus on the front 2 O2s.

 

And here is a tip...

If you find that it is in fact one of the front O2 sensors malfunctioning, then swap it with the back one that has a simmulator on it. Thats assuming you have the simmulators. If you dont then never mind my reply...

 

I thought the back 02 sensor were different part #'s?

I am thinking of getting sims for the back since I really could care less if they are getting real values. Do the sims have to be actually put in the exhaust or are they just a type of unit that plugs into the pigtail. The reason I ask is when i do get an exhaust I will not need to put a bung in.

 

But I was not getting any codes from 02 sensors prior to the emissions test. Maybe I have one that is going to give up the ghost soon. You would think I could see this on my scanmaster however.

 

Dave,
You are right. Sorry for the mis - information. They have different connectors so you couldnt do it if you wanted to. The part numbers are different. Looks like your going to have to go purchase one from the auto parts store.

When I had my 99 Z with LTs and ORP I had the simmulators and they were just attached to the wires and zip tied up out of the way. No bungs were needed in the rear.

 

I actually have 2 spare old o2's that I kept, when I did my header swap. I am just trying to pinpoint which sensor is giving the issue. I do not have a code set by the comp, so that is why I am like

 

hey dave i live in league city and im going to do my inspection today. you said your allowed a few not readys is this correct? i changed alot of parts out lately and finally got things strait i hope.. when i started it back up for the first time in a few weeks i got the same code but the ses never came on. i rest it and it has not came back up on the scanner yet. i wonder if the 02 are wired correctly... the 02s i replaced are the bocsh with four wires two black and two whites you have to butt connect together. i dont know if i wired them correctly or not. been working for a year now so i guess there ok.

 

When doing research on this I have read the two "not ready" alerts are allowed because the new OBDII emissions equipment is notorious for not giving the sensors enough time to respond when they go through the test parameters. It has been stated when this "bug" can be fixed then no grace will be given on any year OBDII vehicle.
Can't remember the source, but when searching around I googled "OBDII testing."

 

Do you mean an actual "Scanmaster LT1"? I didn't think it would read OBD-II codes.