gio89kid

Well it's beginning on week two of having a K&N intake installed on my 2007 2.4L automatic HHR.

It looks great, and I cleaned the maf sensor with CNC maf sensor cleaner which removed all the dirt and could see a difference in cleanliness afterwards.

So I tested it out the first week burning some extra gas to hear the engine sound roar.

But now I have been keeping an eye on the gas gauge and trying to keep the rpms low, which I never did before I got the intake.

Before the intake, the dash said I got an average of 22.5 mpg and I never drove like I was saving gas, after the intake it says I get 22 mpg which is not bad for more performance.

But before the intake, the gas gauge showed that I used to burn about 1/8 of a tank a day, now it seems to burn almost 1/4 of a tank a day while driving the same way as before and a little better when babying it to try to save gas, that would mean I'm getting terrible gas mileage.

So I disconnected the negative terminal of the battery before the second week and have been driving it around now to see if the new fuel trim would help, which I didn't do when initially put it on, nor did I wait at idle or anything that I have been reading now, but I figured the car would adjust itself over time especially since I reset the computer.

So what's going on? Everyone that has posted on the forum that has an intake seem to have good results and don't mention much of a difference of gas mileage at least not burning twice as much.

Here is a day in the life of my driving:
I live high up the freeway so every morning I drive downhill on the freeway usually using like no gas at 2000 rpm, matter of fact when I reset the mpg dic before I leave I get something crazy like 66 mpg. I only go to school during the week, so only one stop, no other driving and then go back home up the steep freeway hill. Which is where I burn most to all of my gas. In order to maintain the correct 65-70mph I have to keep my rpms up to 2500-3000 which is normal driving all around, and 3500-5000-redline when passing, even when the cruise control is on it revs up to get up the freeway. 28 miles one way 56 miles total a day, and that's with only one stop home-school-home.

So today after driving it for two days of week 2 and after fuel trim relearn over the weekend, I noticed it went back to burning an 1/8 of a tank a day, yay!, but when I shut the car off and immediately turned it back on, it dropped another 1/8. So I'm thinking I'll check it tomorrow morning and see where it settles, hopefully it goes back up.

What do you think? I saved up for this intake and have used K&N on many cars with success, but this is only the second intake the rest were drop in filters.

gio89kid

Correct me if I'm wrong, but the whole reason I saved up for the intake was that it was supposed to:
Give a nice performance sound.
Provide more air to the engine resulting in better performance and efficiency. Provide more power when needed for hills or towing. And save gas by making the engine run more efficiently.

And I know this to be true based on other cars with K&N intakes and filter that have benefitted from more airflow.

Lucky

I would recommend checking your fuel use manually. (Math).

The trip computer can be off a bit it only works with calculations based on known engineering. You have changed the air flow which is not in the calculations that the computer uses to figure mileage.

gio89kid

Right I will do that next, and I don't actually remember the true gas mileage I was getting before, just what it said on the dash, I didn't pay close attention to it like I am now. I thought I was getting better mileage before, especially cause back then I had work and school each day which meant more driving, and I seem to visit gas stations more lately. but I don't know for sure, I always relied on the gas mileage displayed on the dash. after this week I should be able to tell.

At the current gas prices being close to what they used to be before the intake, if not lower, $40 should last the week.

But... I will fill up and measure mileage and then fill up and see how many gallons it took to drive that many miles.

gio89kid

Assuming my car is getting the 22 mpgs it says its getting and multiplying that by the 15 gallon tank it has that gives me 330 miles of driving divided by 56 miles driven in a day gives about 6 days of driving on a full tank. Interesting, so i guess if i last the week before i need gas i am looking pretty good since it wasn't completely full when i started this week.

Sorry, sometime I put all my thoughts on these forums, but it can help with the answers, so thank you for everyone participating. :)

Oldblue

Drive it, give it a month and then check your milage with the math.

gio89kid

Will do!

Dbeluscak

I'm having the same problem with the wifes SS. Now I realize I brought this headache on myself installing the gen 3 engine and larger "manually controlled" 256 turbo. Everyday just cruising around (we're still babying only 2k miles on it. the downpipe has to go back to ZZP because it's jammed into the Trans and the lower charge coupler will blow off if I punch it) Anyway, while driving normally everyday I get either P101 or P103. Both are directly related to the MAF.

I'm pretty good at catching it, I can feel the difference in performance and see the pending code before it's confirmed. Clears, no problem. I asked Matt at ZZP if it's the tune, he claims it's not. I used CRC MAF cleaner and my mileage went down (using math) cant trust my display after all the tinkering we've done. Nothing I can do about it until I get HP tuners and hit the dyno. I'm 99% certain it's my MAF calibration, it's been relocated to the lower charge pipe just before the throttle body. I'm certain because I'm watching live data while the wife is driving using my scanner. My short term fuel trims are all over the place. You want it to be 1 to -1 throughout your rpm/gear range. Mine bounces between +8 and -13 (no bueno!)

This is what happens when you go Overboard!

DrLoch

Maybe the sensor is just bad. What size tubing where you now have the MAF installed? Also I have seen issues with regards to the location of the MAF, I.E. is there a bend or turn in the pipe ahead of the MAF? I used an airflow straightener on my Impala SS to get the air flow straight going across the MAF sensor. Honeycomb Airflow Straightener When you get HPT and do a scan you will certainly be able to see it. In my experience when I've seen trims move around that much it was because of turbulence in the tube prior to the MAF.

For specific round sizes see here, http://www.saxonpc.com/100mm-cells-for-100.html

gio89kid

Ok well, after driving a while the car seems to be done tuning itself. The dash still says 22mpg and the gauge seems to not fall as much and I calculated the actual gas mileage to be 22.7mpg.

What do you say?