GOATKILLER

SOMEONE PLEASE HELP ME!!!! I WANT LONGTUBE HEADERS BUT I CANT GET A STRAIGHT ANSWER!!!

1.ARE LONGTUBE HEADERS WITH CATS EMISSIONS LEGAL?????????????
PEOPLE KEEP TELLING ME DIFFERENT STORIES!

2. IF YOU PUT LONGTUBES ON YOUR MUSTANG W HIGH FLOW CATS, DO YOU GET A CHECK ENGINE LIGHT? AND IF SO HOW DO YOU GET RID OF IT???????????????

3.HELP ME PLEASE, HELP ME PLEASE, HELP ME PLEEEEASSSEEE!!!!!!!!!!!!!!!!!!!!!!!!!

CrazyAl

1) In the USA, NO. Longtube headers are NOT emissions legal. Why? Federal emssions laws prohibit changing or moving the OEM cats. Becasue longtubes replace them, or require moving them even if you tried a custom-fab job to keep the stock cats, they are NOT legal.

Now then, that's according to the law. PRACTICALLY SPEAKING you will be OK so long as you run cats. Nobody cares so long as you actually have cats, (unless you get unlucky and get the inspector on a bad day).

2) No, you do not get a CEL with high-flow cats. You only get the engine light if you have NO CATS....and in that case it can be fixed with a tune or O2 sensor simulators.

likemike99

if you live in a state (most of them) that requires them, then yes it is illegal to not have them. when you get long tubes you NEED to get a tune with it as well. this will retune the engine and then you will not get a check engine light

howarmat

1. I think it depends on where you live. Many states dont have emissions testing and some do. I would think with hi-flow cats you should pass any test though.

2. You can turn off the rear sensors with a tuner. Again with cats this might not be a problem.

CrazyAl

Not true. Longtubes generally do not need a tune. I checked my A/F with a wideband meter after installing mine and they did NOT need a tune. You will hear the same thing from all the expert tuners. Call Brent (brenspeed) or Fred (evo) andthey will tell you the exact same thing. Please stop continuing the myth that longtubes need a tune!!.

Also, note that the emissions law regarding the cats is FEDERALand applies to EVERY STATE. Thus, it doesn't matter what state you live in, if you tamper with the OEM cats it is ILLEGAL. Now, I agree completely that if your locality doesn't have inspections or emissions testing then you can get away with it very easily...but it is still technically illegal.

If you want to check for yourself, go ahead: Section 203 of the US Clean Air Act, 42 US Code, Section 7522

vsop

Al-

Actually my LTs with O/R X required Tuning.. The A/F was off after I put the LTs on with the O/R X pipe..


And unless you are in a state like Cali that does Carb number checks a LT with Cats will pass the sniffer and most only do ODBII scans so you should be just fine..

CrazyAl

Yeah, an O/R setup is a little different sometimes.

As for the law, I think we are in agreement. Most areas don't do sniffer tests...and even if they do you will pass ifyou have high-flows on there. But TECHNICALLY it is still illegal under the Clean Air Act, even though your chance of getting caught is Nil.