More on LOUSY Fuel Mileage

[stilbo]

Ok..
My '96 EB 4.0 gets about 17-19 highway mpg w/ stock everything, level ground on interstate loop, 55 degress ambient temp w/ 87 Octane. Snap On code scanner says all operating parameters and input devices are in NORMAL RANGES.
ok....
My '93 XLT 4.0 gets about 11-14 highway milage w/ stock rims-tires, no major mods, Bosch Platinum plogs new wires, $40 air filter, maintained like a Gulfstream IV, same weather conditions and the Snap On code scanner (which is VERY detailed in the information it pulls and displays)shows that all parameters of input devices (including O2 sensors) are operating well within normal range..
I mean even the damn injector voltages, pulse widths, frequency, MAF data... ALL are the same and OK.
The trans is flushed and filled every 50k...
The compression is ok..
No vacuum leaks..
At 150k, could the damn Cat Converter be getting ah... congested or just full of s**t?

What the hell is going on here?

When I bought the '93, it would get 17-19 mpg highway on a BAD day....

WTF?

dr ron

 

[RFR2212]

Originally posted by stilbo
When I bought the '93, it would get 17-19 mpg highway on a BAD day....

Musta been nice... I've never had any of my X's over 15mpg ever... that is mine... My moms new one gets 22 on the interstate rollin nicely... But I finally got 15mpg on the interstate for once in my 94... it was nice havin some gas left at the end of the trip...
Pete

 

[mrit]

I read somewhere that a bad oxygen sensor can cause upto a 75% decrease in mpg

 

[Silverblade]

whats a bad oxygen sensor? am i just a dumbass??

 

[burtonsnow]

the o2 sensor may have gone bad...they are like 50 bucks each for my ranger so i assume the same for the ex...there is one on each side of the y-pipe i believe

 

[mrit]

It is a sensor that measures the amount of oxygen in the exhaust and tells the computer to change the fuel mixture to make the engine run more efficient. It is screwed into the exhaust manifold or exhaust pipes. I dont know where exactly cause I have a Bronco II.

 

[Jason_25]

stilbo, what kinda code scanner do you have? And where did you get it?

 

[aldive]

I have this code scanner http://www.autocheckup.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=achkup&Category_Code=ST2

 

[siberthugd]

O2 sensors

Replacing these are a good thing to do. I replaced mine at 109K miles as I was getting 13-15 MPG. After replacing them i see 18-20. You should also notice a better throttle response. I did them myself but they were a b*tch to do. Unless you have time and patience, it's worth bringing it to a shop to do. I have a lift in my garage, and it still took me 2 hrs easily. They are hard to reach and require 1/4 turns at a time of a wrench. Just my 2 cents worth.