Hey MBWorld, I have a muffler and resonator delete and just passed my smog in September. There's a new smog law in CA now which says that MY2005+ cars would need an OBDII smog instead of the tailpipe smog check. I was thinking of deleting my secondary cats to start off but I would also want Kleemann headers for my car as well (which remove the primary cats) and an ECU tune. Would the ECU be able to see that it has been tuned and fail the smog through OBDII? Is it even worth the trouble or should I keep my current setup?

If it is just OBD II scan I would think as long as you don't have any codes you would be fine, that's what they do in MD. However this is CA and from what I've heard CA tends to be a PIA when it comes to emissions, so idk how through they will check.

who's doing ECU tune? i believe tuner can make changes so that CEL doesn't come on after headers install...
only way to find out is to do smog to see if it passes...
if it doesn't, then there's always a way...

If I get headers, then Kleemann would do the tune. If not, then OE Tuning would be the ECU tuner.

talk to tuner about CEL...

I talked to them and they said that they can do it but since the smog law is new they don't know if the ECU would report it through the OBDII and then fail even though there is no light. That's the problem.

still, there's a solution if it fails...

GA using the OBDII method for emissions testing. I've failed twice since doing headers and ECU. The 1st time was a couple years after the upgrades and was retuned by Kleeman, at no charge, because the issue was in their programming. And they had become aware of the problem before I failed.

The second time I failed was 3 years after the first and was due to a CPS error (OBDII "Not Ready" when connected at emissions station) and pretty much completely opening up the exhaust path (tubing, muffler, resonators, CATS). I had to pay for the second retune.

Get your tune after all your exhaust changes.

I, of course, passed after each incident. I have a reader now, and will know beforehand if it will pass emissions testing before I go for the test.

BTW, there should still be CATS with the Kleeman headers. They may be 100 cell. I replaced mine due to failure, with 200 cell magnaflow metallic CATS.

This is not to say that CA will not have some different methods, but in GA and other states they simply check the OBDII reports that it is ready for test (have no codes), and that the OBDII does not have exhaust specific errors logged. There is a list of items checked (5-8) and there is a minimum number you have to get a "pass" on in order to pass the test.

CA may have a different threshold of line items requiring "pass" in order to pass the overall emissions test. This would be my guess as to why the tuner doesn't know at this point.

I live in CA it might be a obd smog but they check to make sure that all oem emission parts are there. So if you don't have cats and still pass you fail for not having those parts. As for the tune it should pass with flying colors since the tune raises the timing and makes it run better. Also know if yiy fail once you have to smog THREE YEARS IN A ROW not every other year and if a CHP pulls you over and they see you dont have cats you get reffed have to pay a big *** fine and have to go to a state smog station where they check everything to the bolt to make sure you dont have engine mods that mess with emissions again I went through that once and the ticket is 2K+ depending on mods and since they ref you you also cant drive the vehicle since it isnt safe with the mods. Good luck and I hope you enjoy SOCAL lol

I'm not worried about the visual inspection; I'm worried about the actual OBDII test. Now that you mention it, the cops as well haha.

Its only chp. Sheriffs and local cops cant ref omly CHP's. Well if they do visual and it isnt smog exempt they cant pass it since the new star smog is even MORE strict. Back then you were able to pay them 300 and they would do crooked smog. Now you cant.

Just to make sure, I would pass OBDII with a tune (from OE Tuning without headers)? And with Kleemann headers I'd fail smog?

Yes and yes. Even though you pass smog you will fail because visual. You can go with a tune and pass smog because it runs better with a tune with the timing and also because thats something they DONT see

Alright thanks. What mods have you done to your car engine-wise?

I was worried about the ECU tune because I was thinking that the OBDII would realize it has been tampered with and immediately fail the test.

It shouldn't but check with OEtuning or with whatever tune you're going with

I dont have anything done to the benz since everything is expensive and too little of a gain so I just did tein lowering springs, koni yellows, H&R rear sway bar, Str 618 wheels staggered 18x8.5 front and 18x10 rear. I have a mk4 gti that has coilovers,Greddy type RS BOV, N75 valve built bottom end with forged rods and pistons and the list goes on lol its been down for a year and im building a mk1 VW caddy pick up and maybe a VW tiguan might be on the way. Im a die hard vw fan but the benz is the wifes so im considering it mine too lol

Are you saying installation of Kleeman headers for your car require deletion of the CATS or are the CATS replaced with hi-flow CATS?

Kleemann headers removes the primary cats and keeps the stock secondaries but I can choose to install high flow secondaries.

You can pass with cats but if they see you have headers they will ask if they are smog exempt. You might get lucky and find a smog station that doesn't care about visual and will pass you as long as you have cats. Where in California are you moving to?

I'm just worried about the OBDII part of the smog lol

The OBDII part will likely be the least issue.

I would not try running without CATS, in any state. The "secondary CATS", in many cases are resonators and to little to nothing toward eliminating pollution. Mine seemed to be just resonators......

Besides, why would an OEM incur the cost of 3 or 4 CATS when they could just increase the cell count in 2 of them for far less. The only possible reason I could come up with is to not restrict the exhaust flow as much by using lower cell CATS in series. But I don't think this is the case.

The CLK550 has bubble resonators instead of secondary cats unlike the CLK500.

The 500 primary CATS cell must be relatively low (200-300)? If so, wouldn't adding 200 cell CATS to headers leave you very legal?

+1. Same with the m272 350 engine. They're round cylinder versus the secondary cats on the 500s and 320s are little more odd shaped.

I've heard of people passing with their secondary cats off, however, i have no clue under the new laws. In CA, if it's a cat on the car, then I wouldn't touch it.