Devo409

Hello, never been on a forum before, but just bought a new 2014 Lexus IS 250 F-sport and wanted to do a couple things to customize it. So I got a Ingen Cold air intake and just installed it a couple days ago. Very easy to instal and seemed to fit well.

The thing Im wondering is the stock intake system looked pretty intense and had extra features on it (I think it was an extra section on top to increase intake sound?) So I was wondering if it would be better to just leave the original? I wanted to add some horsepower and torque the most cost effective way I could. However, when I put the new intake on and started the car, it started to idol at like 2500 RPM for about a min.. and then slowly lowered to normal around 600-700RPM.. Im assuming it was the computer adjusting to the increase airflow?

Then I have been driving it for a couple days and have noticed the MPG reader getting less millage.. and the eco display not as efficient.. prob a good 4-5 MPG less

Any suggestions on what I should do? Anyone else having this problem?

Thanks
Devon

smardav

Put it back to stock? Is it because your car is still under break-in period? I am pretty happy with my IS250 F-Sport fuel consumption.

STILLEN

That's rather odd. Do you think it might have to do with you stepping on the gas more because of the intake sound?

UncleSpud

I would be surprised if the new intake had a negative impact on mileage. I would be even more surprised if your intake had any discernible effect on HP/TQ. Short of long tube headers (which might get you 15HP), there's very little you can do to these cars to make them faster.

Since the install was easy,why not go back to the stock intake and see if it makes a difference?

IS350S2K

Probably the lower mpg is due to the way the car was driven after the intake install.

And for those who are interested in intakes for performance watch this. http://youtu.be/gCi2yo4UqPI

Devo409

Well I took that into consideration..obviously I was stepping on it to hear and feel new intake. But after that I drive highway to work.. And reset the fuel meter. Before on the highway by keeping it steady about 70MPH the meter would show around 38 MPG... but now it only goes up to about 32 MPG when I hold that speed

HIDPH

iTrader: (5)

I noticed that some people unplug the battery and re-connect it after intake install just to reset the computer/ECU, has something to do with air/fuel ratio and the car's ECU learning when a performance part is installed. Maybe a mechanic or engineer can chime in on this. Just my 2 cents =)

Hermes

Someone on another thread mentioned that Lexus may be coming out with an sport intake, anyone hear anything about this?

vbx

OEM intake is already a cold-air intake. Put the oem back on.

STILLEN

I've had some guys do this on the Q50 and it helps. The computer relearning proper AFR's can help but it should not be that far off TBH. I've heard the Injen intakes on the previous generation IS lost power also.

JGard18

Just save yourself money and frustration and don't try too hard for any power mods on this car. Normally aspirated vehicles require a lot of money and parts to get any significant power gains. Turbo cars are much easier to get cheap power.

With an intake and exhaust on this car, you may see 20hp more than stock (maybe, just an assumption), but you're going to spend $1500 doing it, maybe more. That's not a good value at all.

STILLEN

Last time I checked $100/whp was pretty normal. There are some NA cars that see good gains from bolt ons. The VQ37 gets over 18 whp from our Gen 3 Intakes. Maybe if you come from cheaper cars I guess $500 is a lot to spend on that kind of power ? I feel like most guys who buy a $40k+ car would be willing to drop a few hundred on intake and a grand on exhaust that sound nice and gain some power (even if the power gains aren't mind blowing).

CTLG

I totally agree. I think the problem the 3IS is having currently is a strong aftermarket following in the performance dept. Don't get me wrong, there are some things out there, but so far it all seems slightly half-assed with some decent stuff mixed-in. Also, we need some ECU tuning/reflash help to really make the most of any potential gains.

I think once the aftermarket really gets going on this new car, you'll see more experienced "modders" jumping in as I think the demand is certainly there. I know I have personally sat on the sideline in hopes that some really good/innovative performance options come available soon for my IS350 F Sport. I believe there is still a lot of potential gains locked-up in the new IS, just waiting on some innovation to bring it out.

The 3IS is a great car that people really love. The car carries great public and enthusiast appeal.

toriharper

My parents just leased me my first Lexus! Is it worth while to get it fixed up? I don't want to mess up my mileage but would this intake thing give me more power? Thanks!

corradoMR2

To the OP, not normal your fuel economy is drastically decreased assuming same accelerator input. As some have suggested, either pull the negative terminal out of the battery to reset the ECU, or put back the original.

First, congrats! I have the Takeda intake (see Performance section) and I'm happy with it. I felt the slight gain in performance, but it's small. Sound is great about 3500 rpm but then you'll be wasting more fuel. No noticeable changes in MPGs before and after, when under the same driving conditions of course.

Bang for the buck is not good with an intake and if that's what you're looking for, you're better off spending a little more for an exhaust system, and one that is good value is the Magnaflow, either bolt-on or custom built. Mine was about $900 custom, but the bolt-on version can be had for a little cheaper. Intake and exhaust, combined have reduced my 250 AWD 0-60 times by 0.8 secs, at 7.45 sec.

Good luck.