silverrotor

iTrader: (1)

I did the TB Mod along with removing my Cat.

Currently, my fuel Mileage Is poor. I barely reached 300kms/ per fill up. Where as before I got about 360kms. Mind you that Is city driving.

Does the TB Mod cause poor fuel economy? Or/and the removal of my Cat had a part In It aswell? Or Is their another underlying cause to my crappy fuel economy?

88IntegraLS

If the primary and secondary throttle plates do not open in sequence to spec, you will see a reduction in fuel economy because the plates you removed would have masked the maladjustment a little bit. So pull that TB off and check the adjustment as per a factory service manual or another source of OEM data.

silverrotor

iTrader: (1)

Hmm...What about the Cat removal?

von

want gas buy my GEO metro only 1100 for you. Or buy a miata or honda

88IntegraLS

That should not change gas mileage, certainly not make it worse.. If anything it would make it easier for the engine to work and perhaps cause an increase in mpg. All the catalytic convertor does is clean up the exhaust gasses by burning off the unburnt fuel and carbon monoxide after the engine expels it. It is an exhaust restriction that you have removed.

silverrotor

iTrader: (1)

Ha ha. Already thought of that but decided to stay loyal.

DaleClark

iTrader: (55)

The TB mod should have NO impact on fuel economy, same goes for removing the cats.

Matter of fact, on my car when I was breaking in the last motor many moons ago, with lotsa mods, TB mod, full exhaust, etc. I got exactly 16 mpg in city driving - just what Mazda said the car is supposed to get. Of course, romping on it makes the gas mileage go down on a TurboII when you're firehosing fuel in there to go with the boost .

I would check the usual culprits - O2 sensor and water temp sender.

Dale

fastrotaries

do regular maintenance, i got 27 on the highway with that mod. Along with alot more too.

Ni5mo180SX

Ive done the TB mod and havent noticed a drastic change in gas mileage. I get about 330 miles on a full tank of fuel on the freeway and about 250ish street driving.