GM OBD Readiness monitors - Damn you GM

Lowend

Administrator. .a car, a man, a maraca.
Staff member
Lifetime Gold Member
Mar 25, 1999
16,844
San Jose, CA, USA
I've been trying to get a smog check on my 2002 Corvette for the last week. The weekend before the smog I (stupidly) disconnected the battery to replace a headlight motor forgetting that it would reset the ECM. Failed smog due to non readiness... my fault.

For the last 8 days I've been trying to get the god-dammed O2 heater to go ready. Done the drive cycle/warm up cycle (cold start, 2 min idle with AC/Defrost on - 55MPH drive for 3 min etc... )every day. Everything else is good. Even the EVAP which is supposed to be the tough one clicked over yesterday. No MIL's But HTR icon sits there flashing on my scanner.


I'm just venting - I'm sure like many others I'll drive the car for a few more days and for some mysterious reason the O2 heater will go ready for no apparent reason. Seems to be how it goes with Early 2000's GM's.

I guess I got spoiled by other cars where you just drove them for 50-ish miles and everything went ready with no drama.

<Sigh>
 

Knuckle Dragger

Mayor of Simpleton
Staff member
Lifetime Gold Member
Nov 2, 2002
16,933
Waddell AZ
I've been trying to get a smog check on my 2002 Corvette for the last week. The weekend before the smog I (stupidly) disconnected the battery to replace a headlight motor forgetting that it would reset the ECM. Failed smog due to non readiness... my fault.

For the last 8 days I've been trying to get the god-dammed O2 heater to go ready. Done the drive cycle/warm up cycle (cold start, 2 min idle with AC/Defrost on - 55MPH drive for 3 min etc... )every day. Everything else is good. Even the EVAP which is supposed to be the tough one clicked over yesterday. No MIL's But HTR icon sits there flashing on my scanner.


I'm just venting - I'm sure like many others I'll drive the car for a few more days and for some mysterious reason the O2 heater will go ready for no apparent reason. Seems to be how it goes with Early 2000's GM's.

I guess I got spoiled by other cars where you just drove them for 50-ish miles and everything went ready with no drama.

<Sigh>

Do they all have to be passed? I think you get one not ready and still pass. I very well could be wrong, we didn't check them "back in my day" :)
 

Lowend

Administrator. .a car, a man, a maraca.
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Mar 25, 1999
16,844
San Jose, CA, USA
In CA it's all automated now other than visual. Smog tech plugs into the OBD port and the whole thing runs. If the sensors aren't all up, no dice
 

Knuckle Dragger

Mayor of Simpleton
Staff member
Lifetime Gold Member
Nov 2, 2002
16,933
Waddell AZ
In CA it's all automated now other than visual. Smog tech plugs into the OBD port and the whole thing runs. If the sensors aren't all up, no dice

I get it's automated and the readiness monitors need to be run, but maybe not all of them. Let me look into it.

Yeah, you're stuck getting it to set. California only allows the evap to be "not ready" Weird they got that specific but it's Cali for you. BTW, it's not sensors, they are rediness tests run by the computer to make sure the systems are working correctly.

 
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Lowend

Administrator. .a car, a man, a maraca.
Staff member
Lifetime Gold Member
Mar 25, 1999
16,844
San Jose, CA, USA
From what I understand, it can take months for EVAP to set. CA is being strangely merciful on that one... probably too many people complaining to refs
I've already paid my reg, just can't get my tags until this damed O2 Heater registers.
 

Rosster

Veteran Member
Gold Member
Mar 1, 2020
1,033
I had the exact same thing on my 2001 SS camaro. Drove my favorite road course over 85 miles with freeway thrown in, multiple starts and stops, etc and still wasn’t ready.
 

ULTM8Z

Veteran Member
May 19, 2000
10,713
Los Angeles
Had the same thing happen on my mother in laws 2004 Camry. I forget how many miles she had to drive but it was a lot...
 

1980RS

Veteran Member
Jun 17, 2006
6,546
MN
An 02 Vette is just an old OBD2 system, just go for a long drive to get the long term fuel trims set and you should be fine. The 2 pre cat O2's should light off pretty fast me thinks, the post O2's just monitor oxygen output to see the efficiency of the cat converters.
 




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