CT4-V Emission’s inspection after oil change

[Rob H.]

I took my ‘22 CT4V BW to the local dealership for oil change and state inspection(which in my area includes emissions). Service manager said they changed the oil prior to checking the emissions which “tripped some codes” and it won’t pass emissions until those codes are cleared. He said they had to drive it to get some of the codes cleared and when he talked to me this afternoon he only had “2 of the 6 codes yet to clear”. I checked the My Cadillac app and they took it out 3 different times today for a total of 49 miles!!. Lots of hard acceleration and breaking and 5% of time over 80mph. To me this sounds more like they were joyriding in my Blackwing. Has anyone ever encountered anything like this with oil change and emission testing or is this total bs??

 

[Kanetch]

I took my ‘22 CT4V BW to the local dealership for oil change and state inspection(which in my area includes emissions). Service manager said they changed the oil prior to checking the emissions which “tripped some codes” and it won’t pass emissions until those codes are cleared. He said they had to drive it to get some of the codes cleared and when he talked to me this afternoon he only had “2 of the 6 codes yet to clear”. I checked the My Cadillac app and they took it out 3 different times today for a total of 49 miles!!. Lots of hard acceleration and breaking and 5% of time over 80mph. To me this sounds more like they were joyriding in my Blackwing. Has anyone ever encountered anything like this with oil change and emission testing or is this total bs??

An oil change caused codes? I call bullshit. Plus, they have a damn computer to clear codes as far as I know. I’d start with service manager and work your way up from there. Glad we don’t have emission testing in MI.

 

[rdollie]

Emissions testing for new cars??? Sounds like a money grab by the state to me (don't have that here in WA state.)
This is the first I've heard of this issue BUT I'm not a mechanic. That said, I have an OBDII scanner that does many things including clear codes. I'd inquire what sort of code they're getting they can't reset from their computer/mobile interface??

 

[Rob H.]

Emissions testing for new cars??? Sounds like a money grab by the state to me (don't have that here in WA state.)
This is the first I've heard of this issue BUT I'm not a mechanic. That said, I have an OBDII scanner that does many things including clear codes. I'd inquire what sort of code they're getting they can't reset from their computer/mobile interface??

I will certainly ask that when I pick it up tomorrow. I would have thought that would be a computer fix, not driving around waiting for it to reset itself. And the emissions thing is absolutely a PA money grab.

 

[GTANotch88]

As far as resetting codes to pass state inspection, it's not as simple as clearing a code. When codes are cleared, all the readiness monitors are reset and need to run through certain cycles before it will give a pass. That cycling can not be forced by an obdII reader or tech2.

 

[NewCaddy]

You

I will certainly ask that when I pick it up tomorrow. I would have thought that would be a computer fix, not driving around waiting for it to reset itself. And the emissions thing is absolutely a PA money grab.

You tell them they owe you gas money too!

 

[rdollie]

As far as resetting codes to pass state inspection, it's not as simple as clearing a code. When codes are cleared, all the readiness monitors are reset and need to run through certain cycles before it will give a pass. That cycling can not be forced by an obdII reader or tech2.

My layman's interpretation of what you just said is, we can reset/clear codes with a reader, but the dealership needs to put some miles/time on the car to insure they codes don't come back. Did I get that right?

 

[dstewart51]

I change my own oil, never set codes and I know who is taking it out for a joy ride.

Something does not seem right with their story.

 

[Rob H.]

As far as resetting codes to pass state inspection, it's not as simple as clearing a code. When codes are cleared, all the readiness monitors are reset and need to run through certain cycles before it will give a pass. That cycling can not be forced by an obdII reader or tech2.

Thanks. So if that’s true then maybe the service manager’s explanation may be legit, I guess. Although 49 miles still seems pretty excessive.

 

[Rob H.]

I change my own oil, never set codes and I know who is taking it out for a joy ride.

Something does not seem right with their story.

I often change my own oil too, but it needed to be inspected and also putting new tires on it so figured I get everything done at the same time.

 

[GTANotch88]

My layman's interpretation of what you just said is, we can reset/clear codes with a reader, but the dealership needs to put some miles/time on the car to insure they codes don't come back. Did I get that right?

Not exactly. The cars computers are constantly running tests on all the systems. These tests only complete after a certain number of conditions are met or seen.

The evap/emissions system monitor is usually the one that takes the longest to make "ready". If you try doing obdII emissions inspection with a monitor not ready, it's considered a fail. However, some states/model years allow 1 or 2 monitors to be in a not-ready state.

Most system monitors reach readiness after a drive cycle. I've seen different explanations of what a true "drive cycle" is but here's an example of the process needed to make a car emission inspection ready if any dtc's(diagnostic trouble codes) have been recently cleared/reset...

OBD II Drive Cycle for GM | JUST SMOGS® + Repair

OBD II Drive Cycle complete all readiness monitors for smog check. General Motors: GM, Chevrolet, Buick, Oldsmobile, Pontiac, Saturn

justsmogs.com

 

[M2Cto4BW]

Those jammy feckers. They had to know that would happen and should have given you the option to comeback in a week or 2, after you'd naturally go through the gates during your DD.

 

[OldGoat]

I turned wrenches for 30 years and never tripped a code during an oil change. If for some unknown reason they did at no point does going 80 mph part of a normal drive cycle to clear any codes.

 

[OldGoat]

I would really want to see what codes were tripped

 

[Slick Blackwings]

This whole driving after an oil change because of codes being triggered it’s nonsense had my oil changed at the dealer they drove it in change the oil parked it in front of me. If the dealer had thrown codes out of respect they should’ve called you directly asked you for permission to drive it or for you to come get the car and put a days worth of miles on it and return it to reset or retest. If it were my car I’d be all over them showing the data of their drives.

 

[pmsteinm]

I used to have a really hard time getting my 2001 Oldsmobile Aurora to pass the readiness tests. There was a problem in the transmission that if you didn't accelerate fast enough it would set a code about excessive slipping. But if you drive that way (which I normally do) another test wouldn't complete. And the EVAP test only ran with the gas gauge between 1/4 and 3/4...but the sender was busted so it would usually go from full to empty with nothing in between (except for a narrow window). It would take me days of following the service manual guidance to get all tests ready. Eventually I replaced the fuel sender which made things a lot easier.

I do wonder why they cleared your codes (which also clears the tests). Or perhaps they let the battery die.

 

[M2Cto4BW]

I would really want to see what codes were tripped

This is in reference to California, but I am assuming it is some flavor of these that the OP is dealing with in PA:

https://static.nhtsa.gov/odi/tsbs/2020/MC-10171875-9999.pdf

 

[Finally-a-V]

I can't even spell machanic, but something doesn't seem right. See what I did there? I've changed oil for years. Never set off a code. That said, maybe "todays new cars" are different. They should have contacted you and explained what codes came up, and what your options are. 49 miles seems like a lot, but I'd sure as HELL have someone's ass for any percent over 80. Just my opinion.

 

[M2Cto4BW]

I can't even spell machanic, but something doesn't seem right. See what I did there? I've changed oil for years. Never set off a code. That said, maybe "todays new cars" are different. They should have contacted you and explained what codes came up, and what your options are. 49 miles seems like a lot, but I'd sure as HELL have someone's ass for any percent over 80. Just my opinion.

You're not going to 'see' anything after an oil change unless you think of looking and hook it up and why would anyone do that. There's no way of knowing in DD.

It's the back to back change & test scenario that bubbled it up, which isn't something many will end up doing.

 

[jbawden]

An oil change turning on the MIL? Get the F out of here. I think there is more to the story, but we're not likely to find out. At face value, if they did clear a code, it can take days for some of the monitors like EVAP to go green. They should know this because, you know, they are auto repair professionals.

No reason whatsoever to beat on your car for 50 miles. I'm not one of those that think the car was harmed, at all, but I do think it's all you need to know about the level of respect and integrity of that service department. I good service manager would never allow shenanigans with any customer car, but especially not a BW.