Catless headers emissions

[JCasale]

Has anyone even attempted to get an emissions check with catless longtubes and a tune? i dont have to worry about it for 3 more years since i bought the car new, i was just wondering if theres anyway around it? Here in ohio all they do is hook up to the ODB port and make sure you arent throwing any codes and no CEL light

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[Rypkr937]

Has anyone even attempted to get an emissions check with catless longtubes and a tune? i dont have to worry about it for 3 more years since i bought the car new, i was just wondering if theres anyway around it? Here in ohio all they do is hook up to the ODB port and make sure you arent throwing any codes and no CEL light

Can't a tuner just tune it to tell the computer that all emissions systems (including nonexistent removed ones) are in tact and operating correctly and therefore you'd only need to pass a visual inspection?

 

[JCasale]

thats what i was thinking, they dont do visual here in ohio so aslong as im not throwing any cel i should be ok

Can't a tuner just tune it to tell the computer that all emissions systems (including nonexistent removed ones) are in tact and operating correctly and therefore you'd only need to pass a visual inspection?

 

[Rypkr937]

thats what i was thinking, they dont do visual here in ohio so aslong as im not throwing any cel i should be ok

Don't take that for truth though, I have no experience with this, it's just what I thought.

Anybody else?

 

[Lonmon]

Most tuners that I know of can't or won't be able to fool the emission station. When a tuner gives you a tune for catless headers they usually disable the rear o2 sensors so the check engine light will not come on. That also keeps one of the monitors from achieving a readiness state. All monitors need to be in the readiness state for your car to pass emissions. Your best bet is to have the rear o2 sensors kept on but to use spacers to get the rear o2 sensors out of the direct exhaust stream. This may fool them enough to keep the light out and the readiness state complete long enough to pass emissions. If this doesn't work then you will have to put the factory headers back in to pass emissions. You may be able to get green performance cats installed but I have heard some complain of getting a cel with them as well. It is federally illegal for someone to make a program to completely defeat the readiness monitors and most tuners will not put their lively hoods at stake over it.

 

[choate]

Man oh man I could tell you stories on this situation. I went in thinking the exact same thing as the OP. And this is what a guy that worked at Ford told me too. No CEL, pass visual (looks good to me type of a deal) and you're all set. Wrong!

What everyone has stated above is true though. I first got the not ready monitors. 3 of them. I went back to my tuner and they wrote me a new tune, still after a couple hundred miles the same thing. They then advised to put the cats back on and they'd write a stock type tune. Ok no big deal so I did. Tried again and still the exact same thing. I gave up with them and started asking around and a guy told me he could not pass with his simply because he had a 3" mid pipe but he put the stock one back on (the after cat mid) and said they all became ready after not much driving at all.

I was skeptical b/c anything after cat should not matter but I could not run my stock tune with the CAI on it so I had a shop put everything back securely and to stock (my cats were rattling and I couldn't get it all the way tight on one side and thought that was it) and they too said for some reason it just keeps saying not ready on the 3 monitors. At this point the only thing on the car not 100% stock was the after cat 3" X pipe and resonator deletes (and gt500 mufflers).

I asked the shop is it possibly that with the stock tune, it needs the 2.25" stock mid pipe and a very knowledgeable mechanic said no, it won't matter but if you want we'll put that on for you and try that. They'd had the car for like 2 weeks at this point and tried several times/drive cycles to get the monitors to set.

He then called me the very next day and which I thought was more bad news but he said you are never going to believe this and i'm thinking oh boy, but he goes your sensors all got ready in less than 30 miles after we put the stock H pipe on.

His guy took it home to drive it some and on the way into work the next morning they all were ready. He said you've made a believer out of us. I was over a month past getting my plates renewed. Either get a sophisticated tuner, or put it all back 100% to stock. And as Stone Cold Steve Austin says, that's the bottom line.

 

[SR56]

I've got high flow cats on mine and it still trips the CEL. Luckily, no inspections in FL.

 

[keiths2kgt]

Anybody try hi flow cats with the spacers? Did that work? I've used the spacers before on a cat that went bad and it worked great!

 

[sonicc]

Anybody try hi flow cats with the spacers? Did that work? I've used the spacers before on a cat that went bad and it worked great!

While I do not have experience with this on the Mustang, I do not see a reason why it shouldn't work. I've used this setup on my previous cars and had no issues. As long as they don't do visual inspection and decide to be d!cks if you have aftermarket cats, you should pass without problems. If you still have CEL, add another spacer.

Problem with tuners disabling O2 sensors is: 1) it's basically illegal, and 2) it doesn't disable the sensor, just sets the threshold to a very high number. It can never achieve readiness, so you'll fail that.

He then called me the very next day and which I thought was more bad news but he said you are never going to believe this and i'm thinking oh boy, but he goes your sensors all got ready in less than 30 miles after we put the stock H pipe on.

I have a strong feeling some details have been left out here...anything after the rear o2 sensor wouldn't make difference as far as emissions go. My guess here is they didn't run the car long or far enough for readiness to complete the first couple of times or they made some other changes to the tune. On most cars it takes a few cycles and 100-ish miles before all readiness completes.

 

[SR56]

I've seen the spacers for sale that are made specifically for that purpose. They're a little pricey to buy and then find out they don't work for our application. Does anyone have experience with off the shelf hardware that would work?

 

[sonicc]

I've seen the spacers for sale that are made specifically for that purpose. They're a little pricey to buy and then find out they don't work for our application. Does anyone have experience with off the shelf hardware that would work?

You can always get one from eBay.

The ones made for specific application are pricier because they're made in smaller numbers, but they should fit better due to the angle/placement of the sensor.

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