wifin

Hey guys, so I recently made myself a custom air intake using a Spectre Cone filter and some of their tubing. I connected the vacuum hose using 7/16 rubber hose from autozone and connected it to the plastic nub on the pipe that is made for the vacuum hose. I don't have a heat shield and I need to go get a metal bar piece to bolt the intake in place. (right now it's just hanging there) I know not smart...

Right off the back I noticed much better acceleration and throttle response.

Later I decided to reset the ecu so that it could read the new mod even better.
Well I think something messed up because my mpg has gone way down.
The air intake is the only mod on the jeep and everything else is stock.
Now it is killing my mpg. Did I do something wrong? Or is it because of the intake that my mpg is going down?

Here is how the air intake is now. Thank you for your help it's really needed.

wifin

I also recently got myself the Magnaflow exhaust and pipe from mudfrog, and new 784 injectors...haven't gotten around to putting them in. But will those help as well?

t-dog

Your sucking in hot air with your filter sitting that close to the exhaust manifold

DirtyKK

i agree with the hot air getting pulled into the intake. the exhaust and injectors should help a little. i only gained maybe .5 mpg with the injector upgrade. it mostly has to do with how clean your fuel system is not that it has a better spray pattern.

kyledye25

Sucking hot air shouldnt hurt your gas mileage. You reset your ecu. It went back to factory specs. So your going to get bad gas mileage untill your ecu relearns how you drive and all. Same thing happened to me. Now the more air that filter is letting in will make your motor use more gas. But I would move the filter to the other side at least. There would be less super hot air.

wifin

Didn't know hot air would have that much effect. Guess a heat shield will be a must within the next few days.
And yeah I bought the injectors seeing that it had a better spray pattern and better idle, not so much for any improvement in mpg. I just can't find anyone to weld the exhaust yet, thanks for the help though!

wifin

Does sucking in hot air do any damage to the engine??
And yeah I reset it about 5 days ago

hankthetank

No its just less dense. Meaning less power.

Desert Rat

I have a couple theories on your situation. If the cone filter has increased air flow enough, the O2 sensors may read a lean condition and increase fuel in order to correct for proper fuel trim. I've never heard of a cone style intake setup causing this before but I suppose it could be a possibility.
Second theory. Could it be that the new found get up and go response from the increased airflow might be making your right foot a little heavier? Experience has taught me that if the rigs more responsive, I'm gonna tend to drive it like a sports car.
Just food for thought.
I also agree that resetting the control module may also come into play here.

cherokee90

The hot air intake you made is a piece of **** im not going to sugar coat it. Your more likely to suck up water/mud/trash then with a stock intake. Anyways to the point yeah the hot air will hurt your performance, The sky high Intake air temps(IAT's) will make the computer pull timing making your jeep a turd. take it off and sell it to some dumb kid.

wifin

Well I don't go wheeling so the mud and stuff isn't a problem to me. And yeah I will make the heat shield to help. But it was my first real mod that I made myself, and I'll try to make it work.

cherokee90

If you shield it, it should help. make sure to report back

wifin

Never heard of the o2 sensor theory, but it sounds like something to possibly look into. I bought this XJ used about 5months ago and haven't checked out the sensors yet. If they are bad could that have an effect as well? And how would I fix the possible leaness

BotakBeng

FWIW, ecu would take 50 starts to complete the learning process.

wifin

Well as of right now...I have turned the intake around and have it hanging on the other side of the engine bay and it fits. I haven't had time to go to home depot and get supplies. Gonna have to do a cut out with cardboard then use corrugated plastic for final shield.