I just got an AAM 2.5 inch catback exhaust with AAM testpipes installed on friday and my mileage has gone to ****.(15mpg) How are you other HR guys looking with respect to mileage with test pipes and exhaust cuz with my other car it actually improved mileage?

 

you're lucky to have it at that cuz mine is at 14.5 and no test pipes

 

Wow are you serious man. Thats nuts. You must have your foot to the floor all the time. I was getting around 20mpg before the exhaust and test pipes. I think the car needs to be tuned because I dont see how opening up the exhaust flow kills your mileage that badly.

 

no it usually your right foot that makes the mpg go down. I did the same thing you like the sound of it now so most likely hitting it harder.

 

Lol, maybe for the first few hours that was the case but I'm definitely driving it the same now and the mileage is still in the 15s. Im gonna get it dynoed with A/F numbers to get more info on how its running. This isn't my first I/E car so Im a little used to the sound by now.

 

WOW. I have test pipes catback and intakes and I'm still around 22 mpg. That sucks bro. How often do you get on it?

 

on highway entrance ramps, and every now and then. Im so worried about being pulled over for it being too loud that I have actually been babying it the last two days.

 

it means you need the greddy tt kit.

 

If your willing to sponsor me I'm in

Otherwise I plan on heading to get it dynoed soon with A/F ratios to see if I am running as rich as I think I may be. I just thought that it would be the opposite and I would be running lean after those mods.

 

Give it a little time and see if your mileage gets better. Your PCM will see adjust the fuel trims and lean it out if necessary. Reset the mileage display every gas refill and see if the average goes up.

 

I have a rev up and just installed tp's... mileage is crap now. I just did an ecu reset hopefully it will improve.

 

Yeh I will give that a try and an ecu reset if all else fails

 

wowwwww, i cant believe that man. btw howd you run 13.7 with 283 at the wheels!? stock narrow *** tires i take it? you oughta be around 13 flat

 

his 13.73 was stock wtih just fujita intakes. Not only that hes a track noob
Once he gets his launch down hell be able to hit high 12's with his car.

 

Thanks Jon. Yeh my noobness is primarily the problem. And im sure I didnt have 283 when I hit 13.7 But next season we will see. I have alot to learn so better things to come. By the way Jon, Mo did an overlay of our dynos and they are almost identical so, minus the gears and DRs and my noobness we should be about dead even at the track next time.

 

yup . I have stock intakes with k&n now. Hope to see better results

 

nice. I have mine sitting in the living room and have been debating putting them back on but I will wait to see how it works for you first.

 

Do you guys do the ECU reset by letting it idle for 15-20 minutes?

 

I disconnected the battery for about an hr then hooked everything back up.

 

Poor misguided souls. Resetting your PCM does nothing. NOTHING. It is an old wives tale. The PCM 'learns' certain mods by adjusting the fuel trims, short term and long term. This will happen regardless of whether you disconnect the battery and reset to PCM or not. It will not happen any sooner, or later. It takes drive cycles. There are 'blocks' for a certain load vs. rpm. The more time you spend in that 'block' the sooner the PCM learns and adjusts to it. It has adsolutely nothing to do with being reset.

People frequently get fooled into thinking it works because they reset the PCM, then they drive it like the stole it trying to get it to learn the new mod, and think that made a difference. In reality, if they just drove it like that anyway, the same thing would have happened.

People who reset their PCM have no understanding of the way a modern car and its monitoring systems operate.

Also, certain mods are able to be compensated for by the PCM and some are not. Depending on the manufacturer the fuel trims will either be +/- 15% or the baseline (read: 0) will be 128 and rich will be 129-255 and lean will be 0-127. Two ways of doing the same thing really.

The PCM can only compensate so much. For example, adding a new exhaust which will lean out the mixture will cause the fuel trims to go 'positive', which means adding fuel.

There is a limit though, that's why reflashes are still necessary after a while.

Don't mean to rant, just sick of always reading misinformation.