Lost mpg
Thread Starter
|
New User
Joined: Nov 2012
Posts: 23
Likes: 0
From: Mi
Lost mpg
Ok so this is what i did .... I got a 94 E350 it was running rough so i gave it a tune up , changed 2 bad injectors , changed both o2 sensors & added dual exhaust.
Now before i changed the O2 sensors the exhaust was real strong & i got around 11mpg . Now that i hooked them up i get around 5mpg.
What did i do wrong ??? Feel like im going backwards instead of forward !
Hope someone can help me !!!
Now before i changed the O2 sensors the exhaust was real strong & i got around 11mpg . Now that i hooked them up i get around 5mpg.
What did i do wrong ??? Feel like im going backwards instead of forward !
Hope someone can help me !!!
Posting Guru
Joined: Feb 2007
Posts: 2,351
Likes: 8
11mpg sucks. 5 mpg sucks much worse. With any engine?
Sorry, but "the exhaust was real strong" does not compute.
Have read plenty of stories about Ford Truck Enthusiasts investing serious cash to modify stock exhaust system, only to complain of significant MPG loss & performance issues. Seems that big changes in exhaust back pressure throw off the computer, messing up FI.
Have read plenty of stories about Ford Truck Enthusiasts investing serious cash to modify stock exhaust system, only to complain of significant MPG loss & performance issues. Seems that big changes in exhaust back pressure throw off the computer, messing up FI.
Elder User
Joined: Mar 2012
Posts: 711
Likes: 2
From: Outside of Memphis, TN
You have discovered how dumb the EFI is on these speed density trucks/vans! The ECU literally just guesses almost everything. The only real inputs it has is the MAP sensor, engine temp, intake temp, throttle position, transmission position and o2 sensors. If any of these are wrong, the ECU gets confused and goes into limp/even more guessing mode. I'd scope those o2 sensors you installed to see if they are providing crap signals/bad out of the box. I'd also check those 2 injectors you replaced to see if the replacements are bad and just pouring fuel into the engine.
Thread Starter
|
New User
Joined: Nov 2012
Posts: 23
Likes: 0
From: Mi
I wonder if the dual exhaust is causing the problem . If i unhook the O2 sensors my mpg gets better . I really dont like electronics !!!
My 87 suburban 350 /4 barrel got around 15mpg & it weight around 5,000 lbs . My parents had a Lincoln town car that when we put the dual exhaust on it it ran ok but didnt have much mpg .
Now im wondering what i should do ! I like have true duals but i guess some vehicles aren't designed to run that way . 351w has alot of power
My 87 suburban 350 /4 barrel got around 15mpg & it weight around 5,000 lbs . My parents had a Lincoln town car that when we put the dual exhaust on it it ran ok but didnt have much mpg .
Now im wondering what i should do ! I like have true duals but i guess some vehicles aren't designed to run that way . 351w has alot of power
Elder User
Joined: Mar 2012
Posts: 711
Likes: 2
From: Outside of Memphis, TN
Disconnect the second one. It shouldn't be in use on standard 48 state emissions calibrations and might be causing hell.
Trending Topics
Thread Starter
|
New User
Joined: Nov 2012
Posts: 23
Likes: 0
From: Mi
When i only run one the mpg still sucks ! I tried only runnin one & i was only gettin around 5 mpg. (No o2 sensor's hooked up ....) Strong fumes coming out of the exhaust & i get around 11+ .(Hook 1 or 2 up) I cut the fumes down & i get around 5 !!! Wth! I dont understand !!!!
Im so confused on what to do !!!!
I swear id rather have a Holley 4 barrel !!!!
Im so confused on what to do !!!!
I swear id rather have a Holley 4 barrel !!!!
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
shtse
1987 - 1996 F150 & Larger F-Series Trucks
4
Dec 5, 2007 05:30 PM
cjsteak
Ford Inline Six, 200, 250, 4.9L / 300
8
Apr 30, 2005 02:41 AM
optikal illushun
Ford Inline Six, 200, 250, 4.9L / 300
22
Oct 10, 2003 05:04 AM