I am getting a p0036 and a p0037 code when I went to smog my car and I thought someone could help me as to what I should do about clearing them ?

 

Clearing those DTC’s aren’t going to get you through smog if that is what you’re talking about…the car will need to be diagnosed and fixed properly and then the O2 monitor will have to run and show OK or completed before you can pass.

 

Any cheap OBD code checker can clear them. Based on your other post, as soon as the PCM runs the O2 test and it doesn't see the aft O2 sensors, the code will just set again. Since there's no CEL it's likely the tuner forgot to turn off the test.

This is stock....



This is with them turned off in the tune and no Check Engine Light....



This is what the Tuner likely did....

 

Ok thank you Jim I will need to go to a good tuner then and tell him what happened?

 

Even if the Tuner goes into the file and updates it to turn off the codes, you will still fail CA smog.

When the CA inspection station plugs into the OBD port on the car, the software does two primary checks....1) it verifies the Readiness Monitor are set to "Ready" which tells them the PCM is controlling and adjusting for emissions and 2) it looks at the calibration CVN. The CVN is then matched to what is in the CARB database as OEM or approved aftermarket (for example the tune with the Edelbrock supercharger from years ago was CARB approved). If the CVN that's read is not in the database, the car fails.

No singular custom tune will pass. It's too costly and time consuming to get the CARB approvals. It's why so many bolt on parts do not have CARB EOs...it's not worth the time and money. It used to be that the Diablo handheld tuner did not change the CVN. I don't know if that's still true and even if it is, I don't know if they'll give you a canned tune for your mods since violating emissions laws is expensive. You might consider calling them since I doubt they'd want to put anything in writing on the internet.

So.....How to get the tune to pass. You need an OEM tune via the GM SPS2 system. A dealer can do this, some high end shops can do this, or you can buy and use something like a VX Nano to do it yourself via an AC Delco TDS subscription. *****In addition*****....you will need to reinstall the factory exhaust or modify the existing exhaust to install the aft o2 sensors albeit you are then at risk of failing the visual inspection. Headers are rather obvious! Without the aft (ie Bank 2) o2 sensors, the PCM will run the tests, all the Bank 2 checks will fail, and you'll get DTCs and a Check Engine Light.

Having said all of the above, it's worth putting the car on a lift to see if this car is the 1 in 1000 that had a prior owner who retained the aft o2 sensors with headers. You can also have the shop check the tune to see what was turned off. With headers, there should be a bunch of DTCs that are disabled as shown above.

CA is quickly (some would say already) making it impossible to modify cars manufactured within the last 15-20 years.

 

So the car has cats on it and they are just high flow cats and why wouldnt the o2 sensors still be there? If they are removed then why didnt bank 2 throw any codes? So there are no headers made that are California smog legal? This is getting way too complicated Jim, I dont understand why someone cant put on california smog legal headers and replace the original cats with high flow cats and simply leave the co2 sensors where they are. Why wouldnt it pass smog with that set up? I totally agree with your analogy of companies not being able to spend the money it takes to comply with CA emissions. The owner and founder of Halltech CAI told me that is exactly why his were not legal in California as he could not spend the amount of dollars it would have taken to comply. So how does the smog guy know if the cats are high flow or not ?

 

I do not have a check engine light on and I bought the car from a dealer in AZ and had it shipped here not knowing the car would not pass smog because of a pair of headers installed on it, and a CAI. It really is not that complicated, the car runs perfect and it does not have a check engine light. I will replace the CAI with a stock air intake and one of the Co2 sensors is bad. They do go bad right? I take it to a dealership and have the co2 sensor replaced and ask them to check it to make sure it will pass smog .... why wouldnt it pass a smog test if their are no codes and the headers are legal ?

 

After doing some research I now understand that LT headers are illegal in CA and I am surprised as I did not know that and thank you for all your experienced knowledge as I learned quite a bit from you. I am screwed for buying an out of state car with mods that are illegal in ca. I am not happy now

 

• The car has FOUR o2 sensors, not two from the factory. CA expects all 4 to be in place
• The FRONT sensors (ie Bank 1 Sensor 1 and Bank 2 Sensor 1) are still installed. Those control fuel trims
• The AFT o2 sensors (ie Bank 1 Sensor 2 and Bank 2 Sensor 2) are usually removed during header installs since all they do is monitor cat performance and tell the PCM if the ability of the cats to clean the exhaust is degrading. Removal of the aft o2 sensors in CA is illegal
• The other codes are not being thrown because they were tuned out. As shown previously, I'm pretty sure the Tuner made an error and forgot to turn off the tests that throw the codes you currently have. The Tuner only turned off the CEL
• High Flow cats are illegal in CA unless they are replacing damaged OEM cats *****and***** they are 50 state certified of which most are not
• The OEM cats are bolted to the exhaust manifolds and visible from the engine bay and easily visible under the car if they look with a mirror. High Flow cats attached to the headers and are often not visible. High Flow cats look radically different than OEM cats.

I'm am aware of Zero full length headers for the C7 Corvette that carry a CARB EO number. Ergo, cats or not, the headers are illegal in CA and fail inspection.

You have to understand that this has nothing to do with how well the parts perform. It has everything to do about companies bending the knee and paying the CARB Gods of CA to get an EO that allows the use of their parts in CA legally.

I have assumed you have full length headers since that's what most install. There are also mid-length headers but I believe those are illegal in CA as well since they move the location of the cats

Visually....
CAI - Fail
Headers - Fail
High-flow cats - Fail
X-pipe with no secondary cats - Fail

As mentioned above, I doubt you have aft o2 sensors installed ergo there is nothing to replace. The Tuner failed to turn off the test routine in the software. In addition, there will be no sensor bungs after the high-flow cats to install the sensors into and the factory wiring harness will be too short to reach the sensors if you add bungs into the exhaust pipe so you will also need wiring harness extensions. After you do all this, the car still fails the CA visual inspection and it fails due to the tune unless you have that reflashed to stock as I've said before.


The path of least resistance is to purchase OEM parts. Low mileage excellent condition examples can often be found advertised here, on eBay, and on Facebook Marketplace. For stuff off of Facebook, I only buy local so I can pick stuff up in person and not get scammed. After you buy and install the OEM parts, you will need the PCM reflashed with the OEM tune. Once all this is done, you will need to drive the car so the Readiness Monitors set. The GM Drive Cycle in online via a Google search. Usually the monitors will set after a 100-200 miles of driving.

Take the pile of aftermarket parts and list them for sale here in the C7 Parts for Sale/Wanted subforum. Depending on brand and condition, you'll likely make back enough money to cover the purchase of the OEM parts and perhaps some of the labor cost if you paid to have the parts swapped. Pics and clean parts go a long way to helping sell things. Showing a pile of stuff in a dark garage or laying in the grass in the yard....not enticing to a buyer.

 

Here's an approximate list of the OEM parts you will need

• CAI
• Left and Right exhaust manifolds
• Exhaust manifold bolts may be needed but more likely than not you can reuse the bolts used with the headers
• Exhaust manifold gaskets (OEM are very good and the local dealer will have them) (between manifold and cylinder head)
• Exhaust manifold gaskets (between manifold and catalytic converter)
• Left and Right main catalytic converters
• Aft o2 sensors. They are a different part number than the front sensors. Only use AC Delco (ie OEM). These cars tend to not like aftermarket sensors
• OEM mid-pipe (aka Intermediate Pipe) with secondary cats
• Exhaust donuts that go between the OEM main cats and the mid-pipe

When buying the manifolds/cats/mid-pipe, they are COMMON to the Stingray, Grand Sport, and Z06. That gives you a large population to search/buy from. You'll want to buy used. When you see the dealer prices you'll understand why.

The two pics below show an aftermarket mid-pipe without secondary cats vs the OEM pipe that has the secondary cats




I don't have any pics handy of the main cats or manifolds but there should be plenty online.

 

I wanted to let you know that today I went to the DMV to register my Z06 that had a smog done on it from a person the dealership sent out to me ( mobile smog) and I was able to get my plates and my stickers after paying for the sales tax and all the other fees. I was a bit alarmed when she asked me if the car was here which I said yes and she said go ahead and pull it around to the inspection lane. I parked it and she asked me to lift the hood for her, I was very alarmed now. I lifted the hood and she looked around and told me to close it and meet her back inside. I still had the CAI and the headers installed which she did not say a word about. I am not sure if I got lucky or she just couldnt see the headers. The CAI looks very stock it is a haltech. I am fortunate and wanted to share this with the California Z06 owners out there... Praise the lord!!

 

I believe that the permanent codes will be there until the ECM itself clears it? Someone tell me if I am wrong. Also, if you just cleared it, in WI, it is an automatic fail even if the car is 100% functioning. So pull the battery if you want but you aren't going to clear the permanent code. Assuming everything is fine, you will still fail if it hasn't run through the 13 or so readiness tests. In WI, we don't have visual. My friend's car was running fine and all the emissions counters were good. On the day of the test, the battery died. Took it to the parts house and they changed his battery. Drove it to the test and failed. A week later, it passed with NOTHING done.

 

You definitely lucked out with a less than observant Inspector

 

I believe so, but I did want to share my experience with the forum and hopefully if someone is out there that has my same issues with smog and registration in Ca. which there are plenty no doubt, I hope this experience from beginning to end will help them. If you need help or if your in the same situation as I was let me know as I believe I can help with a couple things. Thank you to 96GS#007 you were very helpful and I wish someday I can know as much or half as much as you do about the Z06. Thanks Again!!