Monitor readiness to pass state inspection

[WNYHooligan]

I installed a new cam a few weeks ago and had the vehicle tuned. Last rewrite was 2 days ago I believe. Probably 100 miles driven since then.

Took it for state inspection today and they said the monitors weren't ready. When I got it back home I checked and it is EVAP and EGR. I looked at the Engine Diagnostics and there are a pile of codes that were changed to No Error Reported by the tuner.

Would any of these things cause the monitor to not set to ready or is it just the lack of drive time since the rewrite?

Slightly related question...if the only thing I did was replace the cam, is there a reason all the codes were changed? Still has full exhaust, cats, sensors, etc.

[blindsquirrel]

(vehicle in question is a 2010 Yukon XL 5.3L LC9)

Disabling a DTC also disables the related diagnostic tests that are required for a readiness monitor to run and pass.

[WNYHooligan]

(vehicle in question is a 2010 Yukon XL 5.3L LC9)

Disabling a DTC also disables the related diagnostic tests that are required for a readiness monitor to run and pass.

Another noob question. When is it considered disabled? When it?s set to no error reported or when the SES Enabled box is unchecked?

[blindsquirrel]

SES unchecked with MIL on first/second still enabled only means that if it fails the test for that DTC it will not turn the light on. No Error means everything related is disabled and does not run the test at all. Most readiness monitors need multiple individual DTC diagnostics to run and pass.

[WNYHooligan]

I understand now. Thank you.


Is there a reason that so many codes were set to No Error Reported for a low lift cam (216/220 .550? 112 LSA) with no other additional mods on the truck? Theoretically could the ones associated with the EVAP and EGR monitors be turned back on?

[blindsquirrel]

Possibly that is just a list of things that tuner automatically disables out of habit? Let's please not get off on the topic of why so many people insist on doing things wrong, we'll be here until the end of time.

I don't see anywhere that a 2010 Yukon even has an EGR valve. Maybe the EGR DTC is just checking another part of the code, seeing that EGR is not fitted, and then saying 'OK, EGR monitor passed'. With the DTC disabled it doesn't check and so the monitor remains not ready forever.

[ls1z01]

Where in the HPT menu to turn on the Readiness for CAT & EVAP?

[SteelGreenStallion]

Another thing that will cause a not ready condition is disconnecting the battery. After power has been shut off, the vehicle has to be driven for quite a while before it will be ready again.