Thinking about blaming my o2 sensors. Varying gas millage..

[Nikos95]

Okay I'm pretty sure my o2 sensors are shot, and my gas milage is varying quite a bit.

On a trip about 150 miles at 75 I averaged about 31mpg
That day was between 90-95 outside all day

On the trip back 150 miles I averaged about 26-27mpg
That day was between 55-60 outside

Engine ran same temp both days, both days my t-tops were off and windows were down, so I can't blame that. My Iat sensor is new, and I have gained quiet a bit of millage since changing that. Plugs, wires also new.

Anything else I might be able to blame here?
This isn't gas either I notice a large difference all the time in large temp differences.

[andrew.brandon]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

very close to the same speed both way? about the same amount of stop and go traffic the same way?

also, its very hard to get the exact MPG with only 150 miles. there is a lot of room for discrepancies with so few miles.

[slow6]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

you didnt say how fast you were going on the way back?

[Nikos95]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

sorry same no traffic either way and 75 on the way back, no stop and go.

[BobbyZ72]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

diffrent gas could be to blam, personaly, i think your car is fine.

[Nikos95]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

Well I have a SES light, but havn't gotten around to getting it tested, only comes on generally after driving above 65-70mph and then only after I slow back down.

I have been noticing this difference beyond that trip for awhile but this was the real kicker cause I planned on having more gas left then that, so it gave me a little more defined, we are talking the same driving only difference is temp outside and a 6mpg difference almost thats a big diff for even gas I would think. And I'm certain being the car was driven for a year without an air box or filter or ait that the o2 sensors are bad.

Just not sure if there is something else I might be missing. I know I run rich when its cold, a little too rich when its below about 50..

[BobbyZ72]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

well, get it scaned and let us know what it says. ;)

[memphis_raines]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

If you're getting that kind of mileage i wouldn't worry about it too much. I average 26-27 mpg and consider myself lucky after hearing what some of these guys are getting......

[slow6]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

but he ought to be getting better gas mileage when its colder...
I guess it doesnt matter since the damed EGR is SOOO HOT.
Thats just weird

[Nikos95]

Re: Thinking about blaming my o2 sensors. Varying gas millage..

but he ought to be getting better gas mileage when its colder...
I guess it doesnt matter since the damed EGR is SOOO HOT.
Thats just weird

Ya I should really delete that pile!
I know I'm getting damn good millage at some times, just wondering why the difference.

I'll tell you though this motor runs clean for 140k miles, after 5k miles my oil comes out like new!