OH boy! I went down this rabbit hole on a Camaro I had! Long story short, NO ONE could clear the damn code! Not even the dealer! They said they had to replace the ECM and "hopefully" that would do it. But "if" a Permanent Code was set again, the process would start over.... I sold the car to my nephew in another state where it had no problems passing...

You did say that the code wasn't set "again" after reflash, so you stand a chance that if you can get the permanent code cleared you would be OK. Are you using MDS to read/clear codes? If so, I don't know how else you can attempt to clear it... You might need to do a NEW ECM and marry it to the other modules etc to get "clean"....

Funny thing was, the car passed the previous 2 times. They just started looking for permanent codes since.... This is why I won't tune my 650. GAH!

 

UPDATE - Just got back from the SMOG station with a fail notice and instructions to drive at least 40 cycles to clear/exempt the (P0442) permanent code.

The bar.ca.gov site says "PDTC presence will be ignored if the vehicle has completed at least 15 warm-up cycles and been driven at least 200 miles since its OBD information was last cleared". I questioned the inspector on this and he said that the test has recently changed to require at least 40 full drive cycles to exempt the P0442 PDTC code.

The shop foreman at McLaren advised me to run multiple drive cycles with between 1/4 and 1/2 tank of gas to try to get the evap test to complete, and so remove the PDTC P0442 code. I guess I will be out driving in the SF Bay Area a lot during the next few weeks. Wave if you see me!

 

UPDATE - Just got back from the SMOG station with a fail notice and instructions to drive at least 40 cycles to clear/exempt the (P0442) permanent code.

The bar.ca.gov site says "PDTC presence will be ignored if the vehicle has completed at least 15 warm-up cycles and been driven at least 200 miles since its OBD information was last cleared". I questioned the inspector on this and he said that the test has recently changed to require at least 40 full drive cycles to exempt the P0442 PDTC code.

The shop foreman at McLaren advised me to run multiple drive cycles with between 1/4 and 1/2 tank of gas to try to get the evap test to complete, and so remove the PDTC P0442 code. I guess I will be out driving in the SF Bay Area a lot during the next few weeks. Wave if you see me!

WOW! They told me I was F'ed!! No other option than to clear the code. No, "It will be ignored"... Hope that flies for ya!

 

UPDATE -

I put another 2 drive cycles in today with 250 miles but no success. Your thoughts, ideas and comments would be appreciated no matter how crazy!

Just sent an email to customer.service@mclaren.com asking them for the magic spell required to clear this code and pass SMOG. Keeping my fingers crossed they respond with the details as there is no way to fit 40 full drive cycles into the 19 days I have left......

Dear Customer Service,

Problem Statement:
I'm having great difficulty getting my 2014 MP4-12C (VIN: SBM11BAA7EW003462) to pass the California SMOG test. The stock ECU fails to set the OBD2 EVAP Readiness Monitor. This shows up as Permanent Diagnostic Trouble Code (PDTC) P0442 when scanning the stored error codes. There are no other stored or pending DTC codes to prevent the EVAP monitoring test from completing. The MIL light is not on.

Impact:
PDTC P0442 unfortunately caused the vehicle to fail the 2023 California BAR SMOG test. I now have just 20 days to pass SMOG and complete the registration process otherwise I must pay a steep financial penalty. Ultimately, if I cannot get it to pass SMOG the state of California can impound the car and force me to scrap it! It is nearly impossible to fit 40 full drive cycles into the 20 days I have left to pass SMOG.

Additional Background Facts:

• The vehicle is completely stock and was checked to ensure it is running the OEM ECU software image by the McLaren dealer I bought it from.
• I am a qualified mechanical engineer with 15 years experience of programming engine management systems. I understand that the vehicle has to complete multiple specific OBD2 Drive Cycles to allow the monitors to run.
• So far I have completed multiple OBD2 drive cycles from a cold startup, covering a total of 950 miles. I still cannot get the EVAP monitors to run and remove the P0442 PDTC.
• The SMOG station engineer that failed the car advised me to run at least 40 drive cycles with 1/4 to 3/4 tank of gas and cover at least 200 miles to try to get the EVAP monitor to set and clear the P0442 PDTC.
• The maintenance shop foreman at my McLaren dealer advised me to run multiple drive cycles with between 1/4 and 1/2 tank of gas to try to get the EVAP tests to complete.

Questions for McLaren Tech:
1. What is the specific OBD2 Drive Cycle required to run the EVAP readiness monitors?
This is an example of what I'm looking for:

• Starting from cold (standing overnight), idle for 5 minutes to enter closed loop
• Drive in stop-and-go traffic for five minutes using smooth acceleration and deceleration.
• Stop and idle for 4 minutes.
• Accelerate smoothly to a constant 55 to 65 mph and hold for five minutes
• Decelerate without changing gear to 20 mph
• Accelerate smoothly back up to 55 to 65 mph and hold for another 5 minutes
• Decelerate without changing gear to 20 mph
• Accelerate smoothly back up to 55 to 65 mph and hold for another 5 minutes
• Decelerate smoothly to a stop and idle for 5 minutes

2. What are the enabling criteria to run the EVAP monitors during the drive cycle?
Examples of the enabling criteria I'm looking for are:

• The malfunction indicator lamp (MIL) must be off
• Barometric pressure exceeds 75 Kpa1.
• At start-up, IAT and ECT is between 45°F and 85°F
• IAT is not more than 2°F greater than ECT
• ECT is not more than 12°F greater than IAT
• Fuel tank level is between 26 percent and 74 percent
• The TPS is between 9 percent and 35 percent
• The EVAP solenoid is at 50 percent pulse width PWM, within 65 seconds of engine run time

If I know what the answers are, I at least have a fighting chance of getting the EVAP monitors to run and pass the SMOG test.

Please, please help me, as I don't want to have to sell this beautiful McLaren masterpiece!

 

You never replied if the MDS was used in an attempt to clear the code in your posts.... If not, I can offer to try to clear it for you for free! I have one here at my house in Green Valley (near Cordelia) that I use on my 650S... Let me know..

 

Hi Chuck - Thanks for your follow up and kind offer

Green Valley is very nice! I'm often out that way riding my Yamaha R1M motorcycle up Wooden Valley. I would love to stop by sometime and say hi in my (new-to-me) 12C.

Permanent Diagnostic Trouble Codes (PDTC) are stored in protected, non-volatile RAM, and cannot be reset by MDS, or any other OBD2 code scanners. This is by design, to prevent people from circumventing SMOG regulations by simply clearing all the codes prior to the test. You can clear only active and pending codes with MDS, but you cannot clear stored PDTCs which point to an emissions problem in the past. This "enhancement" to the SMOG test has been in place since the end of 2019 for all 2010+ vehicles, to close the loophole specifically for EVAP test failures. Unfortunately for me, it is notoriously difficult to get the EVAP monitoring tests to re-run after clearing the codes, which is the only thing that will clear my PDTC P0442!

My McLaren dealer had already cleared the active codes using MDS. The SMOG check found a stored PDTC, P0442, which is not visible to normal scanners. This just means that there was a pinhole sized leak in my 12C's evaporation control system at some time prior to my dealer clearing the codes. There is no longer a leak otherwise I would have an active DTC of P0442.

Early this morning I called and spoke to BAR's Customer Support line and was lucky to get Dave, who knows this problem well. He explained that all I have to do is complete 15 warm up cycles from cold, get retested, and the automated process will pass me, even with PDTC P0442. A warm-up cycle means driving so that the engine coolant temperature rises by at least 40 degrees Fahrenheit after the engine is started and reaches at least 160 degrees Fahrenheit. This means I'm currently busy running short drives of 10-15 minutes to hit operating temp, waiting a couple of hours for cool down and then repeating the cycle. Doing the math it looks like it's going to take me 5 days to get there.

 

My 12C EVAP issue took another more complicated turn this morning. It eventually ran the EVAP test at the start of the 7th warm up cycle and threw a pending DTC P0442. This means I have a real evap system leak that must be smoke tested, located and fixed. I don't currently have a smoke test rig or I would DIY it so I'm now scheduled for a service appointment at McLaren SF 9 am on Monday. 💲💲💲

If anyone has experience diagnosing evap leaks on the 12C, what do you think of the filler flap seal? The design of the seal around the four small flaps that you have to push in with the gas filler spout looks like it will leak like a sieve.

 

See my PM... LAR can help and maybe sooner!

 

It probably doesn't help you much, but the factories don't set readiness by driving, they do it electronically. The VAG tool I have is capable of running this, I don't know if there's an equivalent function available in any of the McLaren tools. It works while the car is stationary and runs a guided function that has you operate the throttle. It sets readiness in a couple of minutes I believe.

 

@invisiblewave Thanks for the tip. If anyone is familiar with an equivalent function in MDS let me know as this will save time running drive cycles post fix to prepare for SMOG.

This has now turned into hunt the pinhole vapor leak in the fuel system. I spoke to Mike at LAR and he kindly scheduled me for a smoke test next week to hopefully find and fix it. I am hoping it is something easy like a hose or the fuel filler capless (11K0192CP), which looks like it could leak like a sieve.

 

For what it’s worth, my Raptor was giving me a random CEL code that pointed to EVAP system as well. After some searching on that forum, it seems to be a pretty common problem with these new cap-less filler systems.

I ordered this little guy on AMZN FloTool 10719 Capless Gas Tank Funnel https://a.co/d/7kbLxXF

Then I sprayed it with some brake clean, and sprayed some around the inside (sparingly) of the filler neck. Then I jammed this sucker in and out like prom night, just for a lot longer [emoji851]

Basically the idea is gas over time turns to varnish crap, and gums up the seal a little bit. Then it truly doesn’t seal very well, which throws the code. They’re pretty sensitive systems and any leak can cause this. It’ll do the same if you fill with the vehicle running. Since doing it, my CEL hasn’t come back.

You can grab one of these at any parts store, I just wasn’t in a hurry.

 

Then I jammed this sucker in and out like prom night, just for a lot longer [emoji851]

 

Thanks for your comments. I cleaned and leak tested the cap-less filler with soap solution. After letting the car heat soak after a run it didn't blow any bubbles. I guess this could be because it already leaked any differential pressure out somewhere else, or because it is sealed up well. Next step is a smoke test on Wednesday at LAR.

 

Hi,

What is the current milage on IC ?
After performing the leak test, incase no leaks found. Check your carbon canister. That might me the cause route for the EVAP fault.

 

Hi,

What is the current milage on IC ?
After performing the leak test, incase no leaks found. Check your carbon canister. That might me the cause route for the EVAP fault.

I have 28k miles on the car. AFAIK the activated carbon in an EVAP canister will last for the lifetime of the vehicle.

My issue is P0442, which is usually set when there is a pressure change (a leak) in the fuel system of >0.2 psi when both purge and EVAP canister valves are closed, measured over 60-75 seconds. This is the equivalent of a 0.020 inch pin hole in the system.

The way I am trying to trigger the EVAP test is to drive at 65 mph for 10-15 minutes with no A/C or accessories on, then coast down to 5 mph in gear, and then rinse and repeat. So far I have logged 10 warm up cycles with no active EVAP codes, and only one pending P0442. My understanding is that if I get to 15 cycles, and still have the permanent P0442, I should be able to pass SMOG. I don't believe pending code P0442 will cause it to fail.

 

This one is now resolved!
Thanks to all your advice, I was able to fix the leak and pass smog this afternoon by completing the 15 drive cycles required to get the exception for the permanent DTC.

 

This one is now resolved!
Thanks to all your advice, I was able to fix the leak and pass smog this afternoon by completing the 15 drive cycles required to get the exception for the permanent DTC.

Awesome! What was the "leak" in the system?

 

I'm in a time crunch (20 days to complete SMOG and registration process in CA), and don't have the time neeed to complete the 15 full drive cycles required for an exception to the EVAP monitor not getting set.

 

FYI....
I just found that if you have MDS or DiagCode, you can manually force the McLaren's DMTL (diagnostic module for tank leakage) system to run the EVAP leakage test. Of course you still have to find the leak if you have one using a smoke test.

More background can be found here.
EVAP Monitor on European Cars: Real World Diagnosis of DMTL Systems

 

Just wanted to set the record straight ofthe info that you got from BAR:

The bar.ca.gov site says "PDTC presence will be ignored if the vehicle has completed at least 15 warm-up cycles and been driven at least 200 miles since its OBD information was last cleared". I questioned the inspector on this and he said that the test has recently changed to require at least 40 full drive cycles to exempt the P0442 PDTC code.

The inspector was incorrect on this. It might take 40 drive cycles to "clear" the PDTC but there was no rule change that required 40 to exempt it during a SMOG check. It is still 200 miles and 15 warm up cycles for the SMOG computer to ignore the PDTC. Glad you got it sorted!

 

God Bless California, and I thought Massachusetts sucked

 

I'm also in California.
I appreciate all of the info here.
I've been waiting for my 12C to be ready to smog test. The registration is paid, but it ran out January due to smog test.
At the time, my secondary air pump wasn't working due to a failed relay. After repairing, I cleared the CEL codes, which was maybe 100 miles ago and 5 trips.

I do have Mclaren MDS, but have just been monitoring for smog readiness using a bluetooth OBDII interface with iOS app.
EVAP Monitor on European Cars: Real World Diagnosis of DMTL Systems - new link. (above was broken)

I conclude I need to drive it more.
OR should I plug in MDS and see if I also have the 0442 code? Or manually run the evap leak test? If it passes its own diagnostic, will it turn off the readiness monitor?
I am tempted to clean the cap as the thrusting action sounds fun!

 

You do not need the EVAP monitor ready to pass a CA smog check. Just go get your test. If they don't want to test it put in a complaint on them with the BAR. We got to deal with enough crap in this state with smog. We should not have to deal with people that do not want to do thier jobs.

The policy is to test every car as it is presented to them. They have no reason to turn you away with an incomplete monitor.

File a Complaint

 

Thank you, Steve.
Would you recommend I do 15 warm up cycles first?
I do want to minimize hassle factor or returning more than once.
(I think your advice is to just go, independent of warm up cycles.)
I don't know if P0442 is a hidden trouble code or if it'd show up with my basic scanner.

Thank you,
Doug

 

Well it says you got no permanent codes. Is there a data section on your scanner where you can read how many warm up cycles you have? Usually under "Datastream" or "live data" look for a PID called WARMS_UPS or something similar. Yea would be a good idea to get 15 warm ups under your belt just in case there is a hidden permanent code in there.
Most modern scanners will read mode 10 that is where they live.

 

Thank you. I found the warm ups PID on one of the iOS OBDII apps I use.
I just changed the front timing chain cover seal and front main crank lip seal. And ran it several times to check for leaks. And also cycled to bleed and top off the coolant. So it sat on my lift through 5 or 6 warm ups. I suspect those don't count with no miles driven.
Appreciate the help!
Doug

 

Thank you. I found the warm ups PID on one of the iOS OBDII apps I use.
I just changed the front timing chain cover seal and front main crank lip seal. And ran it several times to check for leaks. And also cycled to bleed and top off the coolant. So it sat on my lift through 5 or 6 warm ups. I suspect those don't count with no miles driven.
Appreciate the help!
Doug

Ah no they count. You can do 15 warm ups in your drive way if you want Most cars just up to 160 and down 40 degrees is considered a warm up cycle. Then do a 200 mile drive and you are good - That is If you had a Permanent DTC. Thats the only reason the 15/200 matters. I am not sure you do but yea I am not one to trust scanners either especially on cars like these.

 

Ah! OK!
The drive is one 200 mile without shutoff? Or series adding up to 200 miles?
If the prior, then normally, I wouldn't hit that at all. But, would be fun!
Thanks again,
Doug

 

It's 200 cumulative miles since last clearing the DTC codes, so either one or many drives.

 

OK. appreciate it, Carl!

 

Wanted to report back. I passed smog yesterday.
I ended up with about 20 cold starts and 230 miles and the readiness monitors were satisfied. Prior to 70 miles on Sunday (Coronado and back to Encinitas), one evaporative monitor remained.
I didn't even check before going to the smog station, given the great info provided here.
I did buy a plastic funnel so I can cycle my filler at my leisure. AND I will always have a chuckle thinking about the 18 y/o on prom night description as I go to town cycling it.
The tech did find the emissions sticker on the engine hatch, inside corner and also VIN on the door sill. He had me make sure the OBDII connector was making contact and for a time rev the engine between 1500 and 2k rpm.
I had called ahead to make sure the tech didn't drive the car. He said he wouldn't have been able to smog it without my help. Not sure true, but it was uneventful and done in 20 mins.

Thank you,
Doug

 

Great job! Would you be able to share - stock ECU or tweaked?

 

Stock ECM for my car.

 

I know this is an old thread, but for anyone else in California who may see this thread in the future, you can mass SMOG without passing the EVAP monitoring test on cars newer than 1996.