10.5 MPG !

[fdjizm]

Because catless cars pollute the air. Even if you fix the mileage, your car is still an environmental disaster. And for what? There's barely any power to be gained and you put a huge bullseye on your car for cops because of the smell/sound.

Have you ever been to China? They don't give a fuck about the environment and the place is toxic waste dump with air so bad they give recommendations to stay inside some days. Is this what you want for North America?

Nothing against you bro, we are cool. but I can't risk blowing my engine when I put my SC on because of a catalytic converter. and also there are definitely gains to be had from an o/r x.

 

[retfr8flyr]

Without the cats the o2 sensors aren't getting hot enough and the computer is dumping fuel into the system. It's hard enough to get the o2 sensors to work with LTH due to the location further back in the system. Without the cats you really need someone that knows what he is doing to tune the car.

Earl

 

[stkjock]

Thread cleaned up. Please leave the political debate out of the thread.

 

[Enitalp]

When i first removed my cats i was sure it was the tune, asked for a change, the new tune came, same. and since that i changed my tuner and tune many times with many mod and i still have the same result. So it's not the tune. My surprise was seen the MPG dropping that much with just been catless. But as i see, many people have the same "bad" mpg than me, so it must be normal lol.

94tbird at least my car on HW have a good mpg. Your car is insane.

 

[05yellowgt]

Don't give up on looking for problems. You should do some cataloging to check the activity on the O2 sensors and double check for exhaust leaks. Your mileage shouldn't be affected by simply removing the cats.

Sent from my Thunderbolt via Tapatalk

 

[RedMustang]

tune - you need one

yes

 

[94tbird]

FWIW: stock motor inside and out, KB blower at 10psi, electric water pump, off road H pipe and FRPP Stingers, 4.10 gears and a 28" tall tire all highway, cruise control id get 30.2mpg a mix of city/highway id get 22mpg. I was always light on the throttle and used cruise whenever possible to achieve those numbers.

once the cams entered the equation, MPG turned into GPM

 

[b00stedgt]

FWIW: stock motor inside and out, KB blower at 10psi, electric water pump, off road H pipe and FRPP Stingers, 4.10 gears and a 28" tall tire all highway, cruise control id get 30.2mpg a mix of city/highway id get 22mpg. I was always light on the throttle and used cruise whenever possible to achieve those numbers.

once the cams entered the equation, MPG turned into GPM

same here. I put my cams in before the blower but my mpg's went down the tubes with the bump sticks

 

[VTXFrank]

once the cams entered the equation, MPG turned into GPM

ROFLMFAO!!!!

That's how we figure fuel burn rates in a Blackhawk....no, not really. More like pounds per hour. But it was still 3.1GPM!

I had a Torino GT I built up. Spent all my money from the summer on building that engine. Then could barely afford the gas to get to school each day.

 

[white05gt]

It's most likely not an o2 sensor problem, usually if they are slow responding or not working properly they will throw a code.

 

[Enitalp]

It's most likely not an o2 sensor problem, usually if they are slow responding or not working properly they will throw a code.

I did had a slow response code last summer. Erased it, never appear bacK.

 

[Mustangfreak]

Like others have said, you need a tune for the o/r exhaust or have your rear O2's turned off. Mine are off and I get 17-18 city and 26 hwy with my o/r h and 4.10's.

 

[Enitalp]

All my tunes disable my rear O2 sensor.
I ask the 3 different Tuner. Could think of one error in the tune, but 3 ? no.

 

[05yellowgt]

All my tunes disable my rear O2 sensor.
I ask the 3 different Tuner. Could think of one error in the tune, but 3 ? no.

We're more concerned about the front O2 operation and exhaust leaks at this point. Did you have to use O2 sensor harness extenders for your longtubes? I'd get under the car, preferably on a lift and inspect, the O2 wiring, remove the O2 sensors and do a visual inspection, and check the exhaust from header flange to muffler tip for exhaust leaks.

Out of curiosity, are you calculating your mileage manually or going by the trip computer? Do you have non stock size tires and is that accounted for in the tune along with the 4.10's?

 

[Enitalp]

We're more concerned about the front O2 operation and exhaust leaks at this point. Did you have to use O2 sensor harness extenders for your longtubes? I'd get under the car, preferably on a lift and inspect, the O2 wiring, remove the O2 sensors and do a visual inspection, and check the exhaust from header flange to muffler tip for exhaust leaks.

Out of curiosity, are you calculating your mileage manually or going by the trip computer? Do you have non stock size tires and is that accounted for in the tune along with the 4.10's?

When i first switched to catless it was with the OffRoad Prochamber so, no O2 Extenders, and my MPG died immediatly. Then Later i changed for the LTH, where O2 extenders were used, then i switched my exhaust later for another, so my exhaust line was unmounted multiple time (and one more when i did change my whole suspension & driveshaft). So if an exhaust leak was there, the 4 times my car was on the lift & dismounted in pieces , exhaust leak would be caught/fixed/changed. Yeah a visual inspection of the O2 sensor must be done.

And i use the Trip computer to check, but in real life i really had to fill up gas every 160 miles. So the trip computer is somehow true.

 

[05yellowgt]

I'm just convinced there is something fishy going on. I would be getting much better mileage than you if I were running regular gas. I get the same mileage in the city as you do on E85.

 

[RetroGT2006]

In Florida, the cops will leave you alone even if you have a loud exhaust. But the second they smell it, they want to get their mirror out. And Florida has NO, ZERO emissions testing. But they do have Federal laws about Cats.

All the cops around my area don't care about smelling the exhaust. I have gotten pulled over plenty of times(never gotten a ticket in my state) and they did not hassle me at all. He knew i had illegal exhaust and sent me on my way after he commented on it and asked what i had.

When it comes to import owners around here, they get hassled a lot more. My buddy had a 2006 Evo IX MR w/ full bolt ons, cams, cam gears, arp headstuds, meth, etc and he got pulled over for his idle at a light.. The cop knew it was an illegal exhaust and just gave him a 80$ ticket. Not the massive fine he could have given him for No cats. Fl has to be one of the most laid back states for exhaust related stuff, like you said my state has no emissions.