Hi guys,

I just found out I have to get an emission test done. However, I've been driving around with this CEL caused by a fault in the rear catalytic converter. The shop I go to tell me it could be because of a failed oxygen sensor or a bad cat. I'm hoping it is the sensor because I was quoted $2,300 for a new cat.

I recall someone telling me a failed O2 sensor means an automatic fail on emission testing. Is it true?

Thanks.

 

You have a front O2 sensor and a rear O2 sensor. The ECU takes the differential value between what it senses to detect the efficiency of your CAT. If your sensor is bad, then it can't see the difference properly so you can't pass the test. You will not pass the E-test.

Step 1) What is your code? There is no "rear catalytic convertor". Do you mean rear O2 sensor?
Step 2) If so, buy the rear O2 sensor to see if the code goes away.
Step 3) If after buying it, your CEL remains, then your CAT is truly dead.
Step 4) Then to pass you have to get a CAT (buy new or used or borrow).

 

Thanks, Footman. My bad, it is a rear O2 sensor CEL. I'm keeping my fingers crossed hoping it's just the $279 sensor.

 

I thought you can have two parts of the emissions system fail and still pass?.. I had 3 systems (cat, evap and oxygen sensor) fail and got a conditional pass. That being said, I didn't have any CEL due to the COBB. Not sure if that plays a factor.

 

You will never pass an E-test with a CEL related to emissions system components.

 

Just buy a $15 OBD reader on Amazon or e-bay and delete the CEL. I'm not certain that this will help with the e-test, but this is how I delete my CEL when it pops up every 1,000 km or so.

 

every time you delete it you'll reset the ecu's redyness monitors and never get it ready.

 

The shop I went to deleted it, but they told me it came right back.

 

You can't delete it and then go do etest. Like the above person mentioned your ecu needs to be in a "ready" state after it has gathered all the data it needs to figure out that everything is okay.

 

Mine just passed the e-test a few months ago.
with Gutted CAT.
Replace the faulty sensor, clear the codes drive the car for 90-150 kms.
hook up the scanner again to ensure your system is ready, once its ready go for the test.
Make sure CEL is not on, CEL = automatic fail

All the best.