Crappy Gas Mileage 91 legacy

[rweddy]

So my roos has gone done to around 23mpg from closer to 28mpg.

I just tuned with new plugs, wires, filters, oil, did sea foam, etc.

Car has almost 200k on it.

 

Where should I try next??

 

I was thinking maybe oxygen sensor maybe????

Any other ideas?

[bheinen74]

02, then reset the ecu by removal of battery posts for the overnight

[rweddy]

02, then reset the ecu by removal of battery posts for the overnight

 

Thanks I will try this next, Auto Zone/Napa/Checker 02 ?

Or is this an OEM only type part?

[lmdew]

Coolant temp sensor, if it's running rich all the time.

 

How did the plugs look?

 

If you have a good multi meter you can back probe the O2 sensor harness and record the voltage. If my memory serves me correct 0.5 to 5.0 volts is the range. The higher the voltage the richer its running.

[rweddy]

Coolant temp sensor, if it's running rich all the time.

 

How did the plugs look?

 

If you have a good multi meter you can back probe the O2 sensor harness and record the voltage. If my memory serves me correct 0.5 to 5.0 volts is the range. The higher the voltage the richer its running.

 

Thanks Larry

 

The plugs had some white deposits on the end, but nothing major for 30k on them imo. I might swap it anyway since that probably has 200k on it to.

 

So Subaru wants $153 for O2 sensor, Autozone $58. Coolant temp sensor $59 vs $22. Are OEM really worth the 3x cost difference??

[bheinen74]

Thanks Larry

 

The plugs had some white deposits on the end, but nothing major for 30k on them imo. I might swap it anyway since that probably has 200k on it to.

 

So Subaru wants $153 for O2 sensor, Autozone $58. Coolant temp sensor $59 vs $22. Are OEM really worth the 3x cost difference??

 

if you plan to keep the car forever, then yeah oem. The oem ones lasted 200k but non oem will not last that long on avg.

[johnceggleston]

oem online is ~100$.

[naru]

thanks larry

 

the plugs had some white deposits on the end, but nothing major for 30k on them imo. I might swap it anyway since that probably has 200k on it to.

 

So subaru wants $153 for o2 sensor, autozone $58. Coolant temp sensor $59 vs $22. Are oem really worth the 3x cost difference??

 

no!

[johnceggleston]

i'm in the oem camp.

 

i looked at o2 pricing recently and studied bosch and denso from just one vender online.

 

i do not remember which brand was more expensive but one, bosch i think, was more across the board than the other. they were both less than oem. but here is what i found interesting. both denso and bosch made a "regular" class o2 sensor and a "super" class o2. the regular class items were around 50$ - 65$ while the super class were 75 - 90$. this info is from memory so the prices are guestimates, but an 88$ super class o2 is only ~12$ less than oem.

 

i assume that a subaru oem o2 is a super class sensor.

 

any one have any idea what the difference is between regular and super class?

[rweddy]

if you plan to keep the car forever, then yeah oem. The oem ones lasted 200k but non oem will not last that long on avg.

 

Good point, I only use oem filters, tends to be much less death tick with them. I was once in the oem camp only until I started using aftermarket for timing belts and such from on-line vendors. I found a ebay vendor that sells oem quality parts for half and when I compared them side by side with oem these were better quality, the water pump bearings way tighter and impeller was better built too. Now if this was a 2005 or something I might think twice but this is a 91 with 200k on the ticker.

[ericem]

Thanks Larry

 

The plugs had some white deposits on the end, but nothing major for 30k on them imo. I might swap it anyway since that probably has 200k on it to.

 

So Subaru wants $153 for O2 sensor, Autozone $58. Coolant temp sensor $59 vs $22. Are OEM really worth the 3x cost difference??

 

That's odd check online pricing for the same parts OEM. Dealers should be able to match. The coolant temp OEM is $40 here in Canada, so in USA should be $25.

 

https://www.subarugenuineparts.com/oe_parts_cat.html

[rweddy]

That's odd check online pricing for the same parts OEM. Dealers should be able to match. The coolant temp OEM is $40 here in Canada, so in USA should be $25.

 

https://www.subarugenuineparts.com/oe_parts_cat.html

 

That is another issue the only Subaru dealer close to me won't match online, they tell me that with shipping and tax it will be the same. Then I say there is no tax on-line... after awkward moment of silence.... we don't price match.

Edited March 3, 2010 by rweddy

[dgarlepp]

I changed both front wheel bearings and my gas mileage went from 17 to about 25 mpg 95 AWD Legacy. Guess they were dragging.

[johnceggleston]

That is another issue the only Subaru dealer close to me won't match online, they tell me that with shipping and tax it will be the same. They I tell them there is no tax on-line, then after awkward moment of silence.... we don't pride match.

 

shipping maybe, but tax is in addition to the price of the part.

[naru]

i'm in the oem camp.

 

i looked at o2 pricing recently and studied bosch and denso from just one vender online.

 

i do not remember which brand was more expensive but one, bosch i think, was more across the board than the other. they were both less than oem. but here is what i found interesting. both denso and bosch made a "regular" class o2 sensor and a "super" class o2. the regular class items were around 50$ - 65$ while the super class were 75 - 90$. this info is from memory so the prices are guestimates, but an 88$ super class o2 is only ~12$ less than oem.

 

i assume that a subaru oem o2 is a super class sensor.

 

any one have any idea what the difference is between regular and super class?

 

Mostly just the price. Fact is, some people prefer to pay a higher price.Makes them think they are getting something better.

 

Subaru doesn`t manufacture this stuff.

 

Here is an intersting comment from another site on the subject:

 

"OK, fair enough. I did some more research on-line and also spoke with a rep at Bosch USA. Here is what I found out:

 

1) Yes, Super Class vs. Regular Class is marketing hype. It does not exist with Bosch. The retailer admitted the difference was only Exact Fit vs Universal Fit.

 

2) The universal fit and exact fit part for my car have somewhat different sensors, but the rep did not feel the difference was enough to be detectable through either driving performance, gas mileage or emissions.

 

3) The exact fit part is exactly the same as the original. No changes to the design nor materials has been made.

 

4) The smart link connector that comes with the Bosch Universal has been around for some time and has proven itself to be very reliable. The rep recommended it without reservation for anyone looking for a cost effective solution.

 

5) The rep did not believe an O2 sensor that behaved properly when tested by appropriate diagnostic equipment needed to be replaced, regardless of the mileage. "

[rweddy]

Mostly just the price. Fact is, some people prefer to pay a higher price.Makes them think they are getting something better.

 

Well if it cost more it must be better

It is more and more than everyone is using someone else to build their parts.

 

I used to wheel Jeeps and we had a saying that Jeep stood for "just everyone else's parts."