spazzy67

My 91 LS400 w/ 175k miles is getting horrible gas mileage (13-15 mpg) & my exhaust smells herendous. Would changing my oxygen sensors increase mpg & if so, how many sensors does this year have & where are they located?

Also, my rear end is leaking. Could this be a gasket or a seal on the rear differential? easy fix?

Thanks you in advance for any suggestions.
Paul

LiCelsior

iTrader: (32)

www.lexls.com is the site for you, shows u how many o2 sensors there are, and how to read codes. u must have a CEL code.

rear end leak could be many things but maybe search in this forum and see if anyone had the same problem as you.

EastWind

when was the last time it had spark plug wires/spark plugs changed, air filter changed? i don't see any reason to change oxygen sensor if it is not giving you a check engine light with a code suggesting to change them, i would do basic maintenance first. air filter, spark plugs/wires.