Significant MPG change-Dirty K&N?

TrueTexUSN · **Joined:** Thu Jun 13, 2013 11:15 pm **Posts:** 104

So this has happened a couple of times over as many weeks. I have a K&N cold air intake on the KK. I noticed that during a short (less than 13 mile) drive home I had used well OVER a full notch on the fuel gauge.Usually I had been getting between 14-15 MPG on a full tank with my calculations. When I got home, I removed the intake and cleaned the MAF sensor with the approved cleaner. It seemed to return to normal.

I installed a Hypertech Econ Tuner Program for regular fuel at the end of last week and this my first full tank with it and it was doing much better (estimate 16-17 MPG). Then this morning, the same drastic fuel consumption problem on a 15 mile trip into work. Could this be the K&N filter? I have had it on less than 4,000 miles and haven't re-oiled or cleaned it. I was under the assumption that you only cleaned and oiled it every 25,000 miles or if you live in a dusty area or wheel it a lot you clean it sooner. I live in San Diego, so weather isn't a big problem, but it has been damp here the last few days.

Very frustrating since I just bought the Hypertech tuner! :banghead:

I will try cleaning/re-oiling tomorrow when I am off duty, but does anyone think it could be another problem? Fuel filter? Just changed the plugs 2k miles ago and added a catback exhaust as well. Oh and replaced the PCV valve last week! No engine lights and she runs fine (little bit of a rough idle). Pretty frustrated!

Gageraid · **Posted:** Tue Oct 29, 2013 10:20 am

You just got the programmer. All of the parameters probably have not been met yet meaning your computer is still learning how much or how little fuel to use. Give it a few tanks before it knows what to do.
Clean the EGR valve. I just did this and seems to be making a big difference in driveability.
Gas stations switching over to winter blends kill mileage, too.

tommudd · **Posted:** Tue Oct 29, 2013 10:30 am

15 mile trip you can't really tell crap about mileage
Lots of things can and will affect the mileage
including type of gas/temperature outside/stops-starts/speed etc
Install a tuner and only driving it a few miles at a time will take a while to get used to your driving style . You should of taken it out on the open road and did some good stop/starts, cruising for more than 15 miles slowing and speeding up, normal driving.
Also toss the K&N and just go to a good paper filter, way better in the long run.
Exhaust on one of these engines does nothing more than give you some sounds to listen to

tjkj2002 · **Posted:** Tue Oct 29, 2013 11:45 am

On modern fuel injected OBDII engines a dirty air filter does not reduce mpg's,it only reduces power.You actually gain mpg's with a dirty air filter on a new vehicles.

TrueTexUSN · **Joined:** Thu Jun 13, 2013 11:15 pm **Posts:** 104

Copy all, thanks for helpin' the noob.

TrueTexUSN · **Joined:** Thu Jun 13, 2013 11:15 pm **Posts:** 104

Our base gas is pretty awful, but this last tank was from a local gas station. I have driven about 115 miles since the tuner, was just concerned because the same symptom was before and after the tuning and it was a couple of weeks and over 26 gallons apart.

I looked briefly into the location of the EGR valve, where is it located exactly and how would I clean it and with what?
TB or MAF cleaner?

I'll keep an eye on it and do a long drive this weekend. Thanks again.

carlosburitica · **Joined:** Sat Jan 05, 2013 1:07 pm **Posts:** 309

http://www.youtube.com/watch?v=_TO7ZC5N-aA

Gageraid · **Posted:** Wed Oct 30, 2013 12:23 pm

The egr valve is on the driver's side.
viewtopic.php?f=88&t=76774

TrueTexUSN · **Joined:** Thu Jun 13, 2013 11:15 pm **Posts:** 104

That EGR valve is in an interesting place. I took a look at i ltast night, and hopefully get a chance to clean it out tonight. Also, the blue o-ring around the copper tubing into the intake looks pinched. I shouldn't be able to see any of it right? I'll post a pic later before I take it off. I hope cleaning EGR helps, because it still doing the same thing (going down a full notch on a short trip). I was going to top it off this morning to see my actual MPG instead of just the gauge, but the non-military gas station I went to was $.50 higher! No thanks, I'll wait!

Thanks for the suggestions, I cleaned my MAF sensor AGAIN to no avail.

tjkj2002 · **Posted:** Thu Oct 31, 2013 8:39 am

TrueTexUSN wrote:

That EGR valve is in an interesting place. I took a look at i ltast night, and hopefully get a chance to clean it out tonight. Also, the blue o-ring around the copper tubing into the intake looks pinched. I shouldn't be able to see any of it right? I'll post a pic later before I take it off. I hope cleaning EGR helps, because it still doing the same thing (going down a full notch on a short trip). I was going to top it off this morning to see my actual MPG instead of just the gauge, but the non-military gas station I went to was $.50 higher! No thanks, I'll wait!

Thanks for the suggestions, I cleaned my MAF sensor AGAIN to no avail.

The KK has no MAF sensor.

Put a non-oiled filter and ditch the TB spacer and then have a induction cleaning done on the engine.If your close to 30k/60k/90k have the plugs changed(copper core plugs only).Stop buying the cheapest gas you can find,I've seen people gain 2-3mpg's after they stop buying the crap gas.

Oh and the EGR really has nothing to do with mpg's,it's a emission part.Can it effect mpg's? yes but you will notice a very rough running engine well before that and the MIL will light up with a EGR code.

TrueTexUSN · **Joined:** Thu Jun 13, 2013 11:15 pm **Posts:** 104

What is the sensor connected to the air intake tube in between the filter to the throttle body then?

I changed the plugs about 3k miles ago at 53000, platinum ones. From all the verbal lashings people have taken, haha, I was going to do new coppers this weekend.

tjkj2002 · **Posted:** Thu Oct 31, 2013 9:13 am

TrueTexUSN wrote:

What is the sensor connected to the air intake tube in between the filter to the throttle body then?

I changed the plugs about 3k miles ago at 53000, platinum ones. From all the verbal lashings people have taken, haha, I was going to do new coppers this weekend.

That sensor is the AIT sensor(air intake temps sensor) and yes get those platinum plugs out.Champion coppers or NGK coppers(OE plugs) gapped correctly(on emission sticker).

TrueTexUSN · **Joined:** Thu Jun 13, 2013 11:15 pm **Posts:** 104

Well it's been a few tanks with tuner and the best Ive pulled off was 18.2 MPG and almost all of that was Hwy miles. still frustrated with the city hwy miles and watching that dang gas gauge move down a click so fast!

. Guess I'll try the shop cleanings people have suggested, but my tuner has not helped with mpgs, for me anyway.

Gageraid · **Posted:** Sat Nov 16, 2013 11:57 am

TrueTexUSN wrote:

Well it's been a few tanks with tuner and the best Ive pulled off was 18.2 MPG and almost all of that was Hwy miles. still frustrated with the city hwy miles and watching that dang gas gauge move down a click so fast!

. Guess I'll try the shop cleanings people have suggested, but my tuner has not helped with mpgs, for me anyway.

Winter gas blends are not helping either. I would remove the throttle body spacer, too. I had one to try it out, and I didn't like it.

Significant MPG change-Dirty K&N?

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