problems passing inspection Engine computer will NOT read cat converters

[crazywhiteboy90]

ive put tons of miles on my 03 cobra after reflashing the computer and still cant pass inspection. On the motor vehicle report i pass every subject besides the cats. The cats come up as "not ready". After trying many different types of drive cycles I ran out of ideas. I decided to try datalogging the 02 sensors since they are what tells the computer how efficient the cats are. When reading 02 sensor voltage the 2 front sensors fluctuated constantly in the 0.5 to 0.7 range but at one point it spiked as high as 0.962 and as low as 0.232. As far as the rear 02 sensors Bank 1 stayed at 0.00 and never changed. the bank 2 sensor stayed at 0.03 and fluctuated between 0.02 and maxed at 0.04. Does anyone know what this means for the rear 02 sensors?

 

[Parts-is-Parts]

All tuners turn them off.
Ask your tuner to turn them back on and send you a file.

 

[03Steve]

If the intake temps are below 40F the test for the cats won't ever begin or validate.

 

[crazywhiteboy90]

All tuners turn them off.
Ask your tuner to turn them back on and send you a file.

so you dont think its the sensors themselves? or they definately seem like theyre disabled?

 

[crazywhiteboy90]

If the intake temps are below 40F the test for the cats won't ever begin or validate.

if i take it to a dealer do they have anything that can force readiness or force all the monitors to run their tests?

 

[racebronco2]

ive put tons of miles on my 03 cobra after reflashing the computer and still cant pass inspection. On the motor vehicle report i pass every subject besides the cats. The cats come up as "not ready". After trying many different types of drive cycles I ran out of ideas. I decided to try datalogging the 02 sensors since they are what tells the computer how efficient the cats are. When reading 02 sensor voltage the 2 front sensors fluctuated constantly in the 0.5 to 0.7 range but at one point it spiked as high as 0.962 and as low as 0.232. As far as the rear 02 sensors Bank 1 stayed at 0.00 and never changed. the bank 2 sensor stayed at 0.03 and fluctuated between 0.02 and maxed at 0.04. Does anyone know what this means for the rear 02 sensors?

It would help if we knew your mods.
Do you have a tune?
Do you have long tube headers?
Do you still have the factory cats on the car?

 

[cobra1977]

did You put the car back to its factory stock tune????? or is this a mail order tune you recieved from your tuner?.
or did you run the cats with the sensors in there for a while when the tune had them off. You may have damaged the rear 02 sensors because the heaters were not on>

 

[crazywhiteboy90]

did You put the car back to its factory stock tune????? or is this a mail order tune you recieved from your tuner?.
or did you run the cats with the sensors in there for a while when the tune had them off. You may have damaged the rear 02 sensors because the heaters were not on>

I tried unplugging the sensors completely and than running the car for awhile but i got no check engine light. when i put the car back to the factory tune i was getting the same results from the rear 02 sensors while they were plugged in. basically always read 0 or close to 0

 

[sabotage]

That easy.....your car has been tuned and the rear o2s are turned off.......the only way you can complete the readyness monitor for the catalytic converter is if both o2s are functional, its how the pcm runs the catylist monitor it compares upstream o2s and downstream o2s . The readings your getting on the front o2s are completely normal you should see rich lean. Voltage Ranging from 0 to 1 volt.....
.0 lean 1v rich.
Front o2 should be moving really fast up and down .....rich lean rich lean and the rear o2s should be going slowly up then down if the catalyst are good. If there hollow or below efficiency they follow the front o2 sensor pattern because there is nothing happening in the cats...no cumbustion....the hc going in the cat comes out .....so same reading on front and rear o2s.

 

[crazywhiteboy90]

That easy.....your car has been tuned and the rear o2s are turned off.......the only way you can complete the readyness monitor for the catalytic converter is if both o2s are functional, its how the pcm runs the catylist monitor it compares upstream o2s and downstream o2s . The readings your getting on the front o2s are completely normal you should see rich lean. Voltage Ranging from 0 to 1 volt.....
.0 lean 1v rich.
Front o2 should be moving really fast up and down .....rich lean rich lean and the rear o2s should be going slowly up then down if the catalyst are good. If there hollow or below efficiency they follow the front o2 sensor pattern because there is nothing happening in the cats...no cumbustion....the hc going in the cat comes out .....so same reading on front and rear o2s.

so your suggestion would be to either have a new tune with them turned on or flash it back to stock just to complete inspection?

 

[oldmodman]

The absolute best way to pass smog is to re-install the stock program and the stock H-pipe.
Just doing that and then driving for a couple of days should reset all the readiness codes and prepare the car to pass the SMOG test.
And you might even want to put a couple of gallons of E-85 in the tank to lower the HC levels.
Be sure to get the car good and hot before going to the check station.

 

[04Mach1Blurr]

I'm having a similar problem, my car is tuned and has a bassani catted x pipe with O2s turned on and it won't show as ready. Even with the stock mid pipe on

 

[crazywhiteboy90]

hopefully i found the problem. I never spent much time under my car but today decided to take a closer look and discovered the rear 02 sensors had MIL eliminators on it because the previous owner had a catless exhaust. Hopefully after putting some miles on it the cat monitor will go from "not ready" to "ready" and this whole problem will be over :shrug:

 

[crazywhiteboy90]

just data logged again the one sensor is a lot more active with the MIL eliminators out but the other is still at 0.00 does anyone know if this could mean a bad sensor or possibly a bad ground?

 

[03 silver cobra]

How many " not readys" do you have? You are allowed one on a 2001 and newer veh in NC as long as the engine light isn't on

 

[Eatonualive281]

so did you ever get you cat monitor to pass? I couldnt. I even put the stock maf back in and the rear o2s are turned on. Both the monitors for my 02s pass and still I cant get the cat monitor to ready itself.

Does anybody have the parameters or requirments for the Cat monitor drive cycle? Somebody mentioned that the iats have to be over 40 degrees. You also have to have between 1/4 and 3/4 of a tank of fuel also, correct?

The only thing I have turned off in my tune is the EGR, thats it. My evap passed last night, so hopefully my Cat monitor isnt too far behind. I've driven the car 30 or so miles thus far in the past 2 days since flashing the ECU.

 

[testorossa1989]

Just go to JDM performance and get it turned off