I had similar Milage, found my Evap Canister was messed up... Replaced that, Milage got slightly better, but not much.

After that I cleaned my MAF and I'm almost back up to the Milage I had before my Cam/M6/Rearend swap.

 

whats this evap canister do and such? i acciedently broke the plastic line while doin my tb bypass and replaced it witha brake line and all the rubber is dry rotted.. (if anyone can hook me up PM me we'll talk) this bad? and i am gettin horride gas mileage and my car seems to have lost power. i am goin to change the o2s then plugs wires then go from there....

 

i have a auto with cat back and cai with a hpp3, and i am getting crappy mileage as well. usually fill at the 1/4 mark and am getting around 170 or about 16 mpg. i can usually get 12 gallons in the tank. i do plan on getting an ignition soon. hope it helps.

 

Add another A4 car to the list of crappy mileage!!!!!About 150-160.I fillup at 1/4,I think it's slightly over 12 gallons.It does get frustrating only gertting that much.I need to buy a laptop!!

Also it has new plugs,wires and fuel filter.

 

I am not in this to bash but let me ask a question, Everyone here owns a F-body with either a 305 or 350 or bigger. Mostly everyone here knows it is a performance car. Lots of people on this forum talk about high performancing their car to some xtreme. So my question is---If people are worried about gas consumption then why high performance it? If you install a supercharger and then get 5 miles to the gallon (slight exagg) why complain? I bought my camaro not for how much miles I can get; if that was the case I would have bought a 4-banger prelude or another type of rice- although weird enough after I put a 52mm throttle body, flowmaster catback, msd 6t; borla y-pipe, and xtreme energy bumpstick in it I only lost about 50 miles to the gallon. I guess my point is noone buys a sports car for great gas mileage; if you did the nut doesn't fall far from the tree. It also depends on the driving conditions, lot of city driving will kill any cars mileage and highway is always best, using the EXACT octane level will improve your mileage as well like always use 93 and up which you should anyways to keep the injectors and pistons free from carbon buildup. If you have an engine with 10.5:1 CR, you need to run 92 or better anyways since less will cause detonation. Remember I am not bashing at all; just shocked.

 

If you have never replaced your oxygen sensors, I would try that. My mileage dropped on my old daily driver and eventually I figured out that it was the oxygen sensor.


Jason

 

noone is complaining that they are in competition for mileage, and most of us dont mind getting 20 mpg, but there is a problem when someone is getting around 30, and someone else is getting 12. something is wrong, and its not the driver. that is way too big a difference to assume someone has a lead foot. even at full throttle we should be getting 'bout 15 mpg, they are carb approved and must have an established min mpg.

but on the other hand, something as small as tire pressure will net you bad mileage. the o2 sensors are the most likely issue.

 

what dabear said, try replacing the simple things first like the o2 sensors (replace both, not just one) I've heard you should stick with the OEM AC Delco, I have the bosch ones and they seem to be working ok. My block learns and integrators in diacom hover rigth around 128 (right where they should be).

This may have already been mentioned, but replace your fuel filter, check the fuel pressure, MAP sensor etc...

 

i used to get 178 when i was stock

 

ahhh seems Im not the only one with bad gas mileage. I have a post floating around here some where about it. 115miles with 3/4 tank of gas which is about 10mpg with a mix of city/highway driving. No fuel smell under the hood, no fuel on the ground (not when its idling anyway). No black smoke. All that fuel's gotta be going some where though. plugs and wires were changed. figure I'll try the o2s and fuel filter since at 70K miles they are due for a changing anyway.

 

Ironicly, i put the hpp3 on and got almost 50 miles per tank, I went from 150 to almost 200. i also used an injector cleaner, put on the catback, and cai all in the same week though, so i dont know which one helped. i am still putting injector cleaner in every other tank and it helps. on the tanks that i dont use it, i get only abour 180, when i do use it, i get about 200.

 

ill try the o2's , it just sucks gettting crappy milage when my friends moms nissan altama is almost as fast as my car 0-60 and its a four door that gets way better mpg..and then theres the dodge neon turbo, wrx and 350z all almost as fast as me a killing me when it comes to mpg ..ahh.. i want a stall and gears two but then ill get like 100 pre tank.. so i guess that will wait intell winter gas prices

 

I did buy no o2's when I did the cam install last year.I however did not buy AC Delco,bought the NAPA brand.So maybe I should switch them out and maybe new plugs.

When I dyno'd they told me it was running rich(13-1).So I know there is a problem but I don't own a laptop and I'm not bringing the desktop to the garage.

 

what is hpp3??

 

Hypertech Power Programmer 3. Reprograms your computer to get more power and efficiency out of your mods.


Chris