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ferocity02
March 11th, 2013, 06:04 AM
I need to smog my '01 Silverado soon, but my system readiness tests won't complete. I put in a new tune a week ago so I expect them to take awhile, but I've done about 15 drive cycles since and two are still "Not Ready". Here is what the report said this morning:

http://i869.photobucket.com/albums/ab251/ferocity02/01%20Silverado/Capture_zps8fe03c92.jpg

My tune is a stock tune with some adjustments for e-fans, gearing/tire size, desired idle speed and desired idle airflow, and some DTC's switched off for the 4L60E to T56 swap I did. I'm running a 4L60E tune because I can't do a manual segment swap without changing operating systems.

I am also using a 160* thermostat, which runs at 167-170 pretty much whenever I'm moving. Could this not be warm enough for the catalyst and heater O2 sensor tests? I read on another forum that 180* is required for some of the tests to complete.

Here is the "GM Drive Cycle": http://www.lyberty.com/car/drive-cycle.html

I'll try step 2 this afternoon to see if I get the heated O2 sensor to test to complete.

As for the catalyst test in step 7, I never drive 55mph for 5 minutes straight. And frankly, I can't think of anywhere around here to do that.

Are there any PID's I can log in order to see that the tests are currently being executed?

ferocity02
March 11th, 2013, 12:16 PM
Well I tried the cold start steps shown here for the heated O2 sensor:

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.

Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.

First I read my PCM to make sure I had the right tune in there, and didn't know that doing this resets the test results and clears DTC's, so I now had 6 Not Ready's... already off to a bad start. Then I turned the key on and turned on everything I could think of: AC to full blast (also turns on one fan on high), high and low beam headlights, radio, and interior lights, since it said the more electrical load the better. ECT and IAT were both 72F. Started up and let it idle for 3-4 mins. Then I checked the monitor and it still was Not Ready...

One thing it could be is that my PCM thinks the trans is in 2nd gear all the time because of the T56 swap, I'm still running the auto tune. Perhaps it must be in park or neutral?

Then on the drive home I continued to monitor the tests. All but the heated O2 sensor and catalyst were ready in less than 10 mins of city/highway mixed driving staying under 45mph. Then I got on the highway and was going 65mph and within 3-4 mins the catalyst monitor went to ready. Sweet! Not sure what I did differently this time. Usually I go 70mph on the highway. The coolant temp was around 170F. I also had a pending P0300 that was cleared when I read my tune, maybe that was holding it up?

joecar
March 11th, 2013, 04:25 PM
2001 onward are allowed 1 not-ready... when are you going to get smogged...?

ferocity02
March 11th, 2013, 04:57 PM
2001 onward are allowed 1 not-ready... when are you going to get smogged...?

Yeah that's what I read, I was just hoping to get them all ready. Hopefully smogging this week or next.