Bad gas mileage - Need advice please

ok, pre-exhaust my car was getting about 380ish miles on a full tank. After exhaust I was getting about 360. Now, all of the sudden I am getting about 330 miles. I just got a new clutch put in and it seems like that couldn’t be the problem. Anyone have some advice, I was thinking of maybe the fuel filter? Or maybe my spark plugs? I’ve put 25k miles on my car since I’ve had it, and haven’t replaced the fuel filter… well, thanks for the advice, because I’d like to save that extra $3.80 (2 gallons) the way gas prices have been lately. :vomit:

spark plugs, spark plug wires, vavle adjustment, o2 sensors, air filter, gas filter, low air compression in tires, bad cap and rotor, injectors are dirty

u can try doing a compression test on the engine itself see what it comes up with

reset the ecu and lighten your foot

Gez, I wish I could get 300 MPT… I am getting 240 MPT at most. And no, My car is not running Rich,

I used to get 300…Im at about 240-260 right now:tsk: somethings wrong and I can’t figure it out. Got to work on it when it finally gets sunny here.

Before I got my exhaust the most miles I have ever had on a tank of gas was 396 and I think it calculated to be about 31 mpg, but it’s just been downhill from there. :stuck_out_tongue:

im only getting like 20 mpg with my 94 gsr swap i would love to get like 300 miles for a tank
my setup stock gsr intake,2 1/4 exhaust bosch platinum2 plugs,ls trannyys1, motor has 78k on it

ecu codes that have been coming up i need to know how to fix these
code 20-electronic load detector
code 43-fuel system supply
code-23- knock sensor

i think maybe certain things are not wired up right does anyone have any wireing diagrams for this stuff because im running a stock b18a wiring harness and a p72 ecu for gsr.

fuel filter was changed,plugs and wires are changed as well as intake filter