Bad Gas mileage (O2 Sensor?)

[NViejeP]

Yah I might attempt to clean the MAF this weekend. How much is the electric cleaner?

Also my dad said he'd pay for a tune up at 70k. I'm like 400 miles away.

 

[trdtoyotaguy]

maf cleaner

like 5 bucks i saw some at nappa , also let me know if it woks and how hard it is ?

 

[jmtreetop]

My 18+ MPG was city/highway mix although my 9 MPG was just highway. It was a considerable different from when the O2 sensor worked and when it didn't.

 

[trdtoyotaguy]

o2 sensor

There are 2 on the 3.4l am i correct how would you know which one had gone bad ?

 

[jmtreetop]

That is correct. There are 2 on the 98 4runner. Toyota can hook up their scanner with the car running and monitor each O2 individually. One was barely working and the other was intermittently working.