JJCNSX

hi all,

i am currently getting 20~21MPG (combined city/highway) on my 98.5 2.8Q V30 with 112k miles.. It's 5spds, i drive fairly gentle..

I am wondering if i should replace the 02 sensors, but, they are about $150 a piece, and 3 of them (2 pre cat, 1 after) are about $450.... They said the life expectancy on 02 are about 90k miles...

Should i replace them or not? I dont see CEL on 02 sensor (i do see CEL on knock sensor and 2ndary air injector..) Would i see any improvement on gas mileage?

-jjc.

Keyless Chuck

Check out Bosch4less.com

JJCNSX

which one should i get? there is two different P/N (OE- Downstream).. http://bosch4less.com/index.cfm?display=display_result.cfm&xmake=AUD I&xmodel=A4%20QUATTRO&xyear=1998&xcyli nders=V6&xsubmodel=&xliters=2.8&xfuel= GAS

not sure which one i should get for my 98.5 30v 2.8Q..

-jjc.

BSK

after 100k i would change them

JJCNSX

i thought it was 2 before cat, and 1 after..

but, it seems like there are left/right (brown/green)after cat.....'

does that mean i need 4 02 sensors?

****tt...

-jjc.

Silver Streakin'

if you don't have a code for it... don't fix what ain't broken.

jguthrie

I know it's 2 post cat. Don't know how many before cat.

S4iowa

2nd. I have 155K on mine. And still get good MPG

MyaLover

My 2.8's gas mileage just dropped too.......Did you try anything else to see if you could get it up?

Keyless Chuck

My 2000 2.8 dropped mileage after I installed 18s, anyone else?