SteelTownStang

I'm thinking about going this route... I don't want to eliminate the cats, but go with a high-flow cat set-up. How will they effect state emissions? What brand are most using? Are they a simple bolt-on? Will I have to get new tunes? Thanks

m05fastbackGT

Pat, if you're concerned about the emission inspection/laws here in PA ? I hope your aware that if you put 6000 miles or less per year on you're Mustang as I do ? you qualify for exemption status which also excludes the visual inspection as well.. Also under the exemption status, your only required to pass the state safety inspection which doesn't apply to cats anyhow.. As for high flow cats themselves ? I may not be an expert on this but from what I've heard from others, there's very little to be gained from them over stock being the factory cats are considered as both efficient and very low restrictive to begin with which is the main reason why most recommend going with either an off road H or X pipe instead.. In fact I'll be upgrading to either the Pypes or Magnaflow o/r H-pipe ? depending on which has the best pricing.. As for needing a new tune ? I'm not sure if you would need a revised tune or not Pat, I know if you go into your end user adjustability menu in the X-CAL II under optional parameters there's an option for shutting off the O2 sensors.. But just to be on the safe side ? I would definitely ask for Doug's advice before messing around with anything that you may not be sure about..

LEO_06GT

My understanding is that highflow cats are just as illegal as no cats.

m05fastbackGT

If you reside in a state that requires emission inspection ? then yes that's correct being that your in violation of both state and federal law anytime the factory cats are removed from the vehicle even if replaced with an aftermarket set up..The only way of getting around it ? is if you reside in a state that has an exemption policy in which my state does..

70MACH1OWNER

Hey Steel,
Save your money. Since you are running a JLT CAI and Dougs 93 octane tune my bet is your car will not pass emissions check right now even with the factory cats in place. I am 99% sure your rear O2 sensors are already turned off. As soon as we all decided to go with a CAI with an updated tune we all gave up our rights to pass an emissions check. Have you ever seen any of the tuners say their tunes would pass. No way. They are for off road use only. So... why try to stay a little bit legal. Pull off that H-pipe and go fully off road.
Scott

m05fastbackGT

Sorry Scott but I must respectfully disagree, I also have Doug's 93 race tune and being that my Stang still has the factory cats in place ? the rear 02 sensors are still on as a matter of fact, I asked Doug about that personally.. Although I don't know anything about how your emission requirements/laws are set up in Ohio ? I do know under the Pennsylvania emission laws that unless the motorist qualifies under the state's exemption policy ? they are in direct violation of both federal and state law which clearly prohibits any individual from removing any type of factory equipped device that's designed exclusively for emission purposes and is subject to both fine and imprisonment upon conviction...and just in case you may be curious ? there's also a visual inspection under the PA. emission requirements in which any Ford dealer will know if the factory cats were swapped out and unfortunately once again, the only way of getting around this ? is if the motorist qualifies under the state's exemption policy..

metroplex

the stock cats look pretty high flow to me.

70MACH1OWNER

Rocky,
I think you are missing my point. Here is Ohio they just stopped E-check in about 20 counties around the state last year after about 20 yrs. of testing. When I say you car will not pass an emissions test with your present CAI and tune I am talking the sniffer test... not visual to see you if your cats are in place. So my point being you can't pass that test than go all the way and take off the cats. Put them back on when you get checked. As far as the rear O2 sensors goes I know most are turned off because the air fuel ratio is different than stock and will confuse the computer. I am running Lidio's 93 octane tune and I know mine are turned off. Brent from Brentspeed also turns them off in his tunes. I also thought Doug turned them off also. That's why guys can run offroad H-pipes and get no CEL's. P.S. I do know what I am suggesting in against the law BTW.
Scott

cobra4548

That's why I love Oklahoma. No emissions testing. We can use whatever we want

RKNMACH

I believe in Virginia they don't do the sniffer for the 2006, they just plug into the port to chweck emmissions. If you aren't throwing codes you should be ok.

RRRoamer

Exactly what does the rear O2 sensors have to do with the vehicles A/F ratio? The only point to them is to test the function of the cats themselves. They simply sit there and make sure the cat IS burning up all the extra fuel left in the exhaust by reading the excess O2. If it decreases the proper amount, then the cats are functioning and the computer is happy.

This is why you DO have to disable the to rear O2 sensors if you install an off-road H-pipe: No cats, so no reduction in O2 between front and rear O2 sensors, so the computer throws a code.

But just changing your tune shouldn't have any impact on the functionality of the rear O2 sensors.

TillmanSpeed

They're talking about for emissions purposes, that you cannot have any CEL's at the time of inspection. If you're running offroad, they would turn them off in the tune in order to pass emissions, and for the annoying light to stop coming on.

He means that the AFR would change BEHIND the cats. That's why wideband o2s read from before the cats to get accurate readings.

CR
Tillman Speed

70MACH1OWNER

Well said CR.
Scott

Lowe!

Well, here is what just happened to me. I live in Austin Texas and I have a CAI and 93 Octane tune from Brenspeed. Stock exhaust, except the mufflers. I went to get my 05 GT inspected a minuet ago, and it FAILED emissions. The reason: The O2 sensors were "not ready", nor was the "Evap Monitor", "Catalyst Monitor", nor the "O2 Sensor Heater", WTF that is. I am assuming my rear O2 sensors were turned off. The inspector said if any one of those 4 Moniotrs was "ready" I'd pass.

I tried calling Brenspeed, but apearantly they are in a blizzard right now and Brent needs to be at home, rightfully so. They did call back quickly and he'll have to check the tune file tomorrow. Sometimes the sensors are turned off sometimes the aren't. Does anyone know if the rear O2 sensors are usually turned off with custom tunes?

There is one other possibility, that the inspector dismised, but I'm not so sure. When he was entering the vehicle information into the computer analyzer, he selected FORD, GT!?! Not FORD, MUSTANG, 4.6L. I wonder if the analyzer was looking for some "Monitors" that exist on the GT but not on the Mustangs??? My report shows I have a 5.4 L engine....don't I wish. I talked to the inspector again. The vehicle setting don't really matter for the emissions test. The ECU tells the analyzer what is ready or not.

Oh, and NO fault codes.

Looks like I'm reinstalling the stock airbox and tune for a few hours....

neil07gt

Nowadays (and in many states), the emission inspection test merely involves checking to see if you have any OBDII codes (check engine lights). High-flow cats are still not legal it the eyes of the law. But as long as you are not throwing any codes and its obvious (to the untrained eye) that you have cats. I don't think the inspector will be any wiser.

70MACH1OWNER

What I am trying to say is that a our cars with a aftermarket CAI and a non stock tune will not pass a sniffer test like they preformed here in Ohio until last year. They have stopped as of the end of 2006. Our cars will be "out of spec" as far as the CO2 and NO2 emissions are concerned. In fact the air-fuel ratio is changed by the tuners. Ford usually has our cars set on the safe side. (Rich) The tuners lean them out to get more power. The parameters of what the stock engines emissions was has been changed. So... since their is no such thing as a little bit illegal I am just telling Steeltownstang to go all the way and pull remove the cats. If you don't believe me ask the tuners if their tunes will pass the sniffer test.
Scott

metroplex

What the inspections facilities SHOULD check is to see if your Rear O2 sensors are physically there and functioning properly. Off-road pipes will fail a visual inspection.

70MACH1OWNER

This is exactly what I have been trying to say. Our cars will not pass emissions test with these CAI and hyped up tunes. Now if you only are checking to see if there are any codes going thru the OBDII you should be fine if your stock cats are in place and assuming they do only a visual inspection.
Scott

neil07gt

If we are strictly talking about a visual inspection...The O/R pipe that I am familiar with has bungs for the rear O2 sensors, which means your O2 sensors will still physically be there. The O/R pipe will fail a visual inspection for the simple reason that your cats are there.

BTW, if you google it, you can see how to make your own mil emliminators with a few dollars and few parts from RadioShack.

metroplex

The first thing the inspector is going to notice with an off-road pipe is the lack of cats (violation of federal emissions law/regulations). Regarding the rear O2 sensors, the inspectors should physically check for the presence on a system with cats.

Typical tunes disable the rear o2 sensors, so ideally the inspectors should then check to see, via the OBD-II system, if the rear O2 sensors are active and functioning to see if the operator of the vehicle is using a non-factory certified engine calibration and if the operator/owner is using MIL eliminators. They could then tie their electronic database system in with the dealership system to void the warranties based on findings of non-factory certified calibrations.