Emissions not ready

smason

Original poster
Member
Apr 12, 2012
4
Hello GMTNation.
I have a 2006 Trailblazer. I had several codes that needed to be fixed before my emissions testing was due. I cleared up everything except p0463 (fuel gauge isn't working). I have driven it almost 1000 miles and still the emissions test says not ready. All I can see is the O2 sensor is not complete. What does it take to get this thing ready so I can get it inspected?

Thanks
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
Typically 3, and perhaps 5 "drive cycles", which are starting from cold, driving a bit until it's warm, then shutting down overnight. 3 days max. Your code either isn't really fixed, or the fuel level sensor circuit is an emission test requirement and you have to get it fixed. 2006 should be covered by a special GM warranty extension. Call the dealer with your VIN and find out.
 

smason

Original poster
Member
Apr 12, 2012
4
It isn't that it has failed the emissions test, it just says the O2 sensor isn't ready. And, there are not other codes coming up. Just the p0463.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
What exactly is saying "O2 sensor not ready"? An emission testing station or some cheap code scanning tool? Could it be that the scan tool is misinterpreting the P0463 as a sensor problem? Why not get that fixed and go in with a clean vehicle with no codes?

If an O2 sensor has a problem, it should set another code. One that can be read and fixed.
 

MAY03LT

Member
Nov 18, 2011
3,426
Delmarva
If catalyst and evap are ready it's not anything that you're doing, you drove it enough. Since all of the other monitors ran, I don't think that the fuel gauge issue is related. If it was then it should have effected the others.

There are ten o2 DTCs (not including the ho2s) that have to pass for a ready status. And, two of them won't show up on a generic obd2 scan tool if they set a dtc. With a good scan tool you can isolate the specific dtc that has not ran and focus on getting its specific test to run.
 

jham

Member
Nov 20, 2011
1,334
Just curious how many miles are on the truck? Since there is the federal emissions warranties in place I believe it's 90000 miles and 7 years iirc
 

smason

Original poster
Member
Apr 12, 2012
4
Thanks for all the replies and sorry to be getting back so late. Busy week/weekend. To answer roadie's question, yes it was a cheap obd2 scanner saying that the o2 sensor was not ready. However, I took it to the dealership and had them go ahead with the fuel sensor fix and had them inspect it. All is good. Next time I won't trust the cheap obd2 reader. But, man this thing has given me a tough few months evap solenoid, thermostat, cpas, fuel sensor and this weekend battery. Hope I'm done for a while.

Thanks again for all this insight. I fixed most of the issues myself using info from here and the "old site".
 

SAR85

Member
Jan 31, 2012
74
I believe some DTCs beig set will prevent related diagnostic test(s) from running, which may explain your issue. Whatever the case, glad you got it fixed.
 

91RS

Member
Dec 4, 2011
105
If the check engine light isn't on, it doesn't matter what codes are stored. All that matters is if the I/M tests have run and passed (some states may be different, but in GA the evap test doesn't have to be ran to pass an emissions test). There is a specific OBD 2 drive cycle that can be followed to get all the tests to run. O2 sensor (and heater) tests will only run on a cold start. And yes, if the fuel level sender code is failed to where the check engine light is on you won't pass an emissions test.
 

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