'93 Hatch, B18B w/ 120k miles on it.

Car has only gotten lighter since I've owned it.
Replaced air filter (on whale *****) w/ K&N very recently. Didn't use their lube ****.
New plugs, wires, and fuel filter in the last 20k miles.
Tire pressures are correct, axles are healthy, brakes aren't dragging.

Used to get 34-40mpg. Got 22 on my last tank, which had a good amount of highway driving.

Any ideas on where my fuel economy has gone? I drive the car maybe 200 miles per month so I'm not losing my **** over this... just wondering.

 

sounds like your O2 is going bad... but not bad enough to set the CEL yet.

 

Not to thread jack as this seems relevant,
but should changing any sensors (ie. O2 sensor) be part
of a regular tune-up?

Cause i have about 125K miles on my civic and I've never changed
a sensor, and I've recently noticed a decline in gas mileage.

 

IMO, decline in MPG + haven't replaced O2 in last >50k miles = replace O2.
(I think I've been reading too much code recently)

 

Any quick How-Tos on replacing an O2 sensor?
And good place to get it? Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Re3irth &raquo;</TD></TR><TR><TD CLASS="quote">Any quick How-Tos on replacing an O2 sensor?
And good place to get it? Thanks.
</TD></TR></TABLE>

Get the car up in the air with some good jackstands.

Remove 02. That's it

 

the motor is obd2. would y'all recommend replacing both sensors?

 

Not unless you just want to. The secondary o2 has nothing to do with mpg or emissions it simply just tells your ecu whether your cat is in good working condition or not. So unless your throwing a code for it just leave it alone. The primary however I would replace. I'm having the same problem as you and I will be replacing my primary o2 in the next day or so.

 

kickass, thanks! should be able to get to it tonight and will have results in a few weeks (once i burn a few gallons).

 

The PCV valve might need replacing to. Shake it to find out...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blk92_d16 &raquo;</TD></TR><TR><TD CLASS="quote">The PCV valve might need replacing to. Shake it to find out...</TD></TR></TABLE>

how would that effect fuel economy? i could see how it being faulty might damage the engine, but don't see how it effects fuel consumption.

 

Yea if you replace it please let me know if it helps bc I'm wanting to try it on mine also.

 

when you get your new o2 sensor make sure you get a Denso o2 and not Bosch...Bosch sucks in honda's (in my experience and what others have told me)

 

Very true elektronsi... Denso makes the OEM o2 sensors so go with Denso. NGK also makes good o2 sensors. I've heard of Bosch sensors going bad after a month on Hondas. Dont cheap out on this.

 

oops, i got a bosch will try to find a denso locally tomorrow... don't think advance had them.

 

How much does a typical Denso cost?

 

Heres a link...

http://www.densoproducts.com/r...yID=2

Theyre damn expensive but theyre worth it. If your primary o2 is bad it can improve around 100mpg per tank. With gas prices the way they are now it will pay itself off in no time.

This may not be the best place to get one I was just showing you guys. Im going to search around and try to find one cheaper.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iluvmy2000civicex &raquo;</TD></TR><TR><TD CLASS="quote">Heres a link...

http://www.densoproducts.com/r...yID=2

Theyre damn expensive but theyre worth it. If your primary o2 is bad it can improve around 100mpg per tank. With gas prices the way they are now it will pay itself off in no time.

This may not be the best place to get one I was just showing you guys. Im going to search around and try to find one cheaper.</TD></TR></TABLE>

thats one of the cheapest places i've seen, the local auto store wanted $172 for a P.O.S. Bosch primary o2

 

Haha exactly... I went to Advance Auto Parts and thats what they wanted for the Bosch o2. I'm going to go back and see if they can order NGK or Denso and if not then I will be ordering from that link or another online.

 

the above site shows $92 for the b-series o2 sensor. that's $30 less than the bosch i got today.

234-4011 sound right?

 

is there a consensus? ntk (ngk) or denso?

 

denso is 125 at vatozone.. i'll be going that route.

 

Yea Denso if def the way 2 go. OEM!

 

I got the same problem, but I replaced my O2 sensor three months ago (when it was throwing a code). Replaced with a Bosch one. was only $70? I'm talking about the one you can access from the top

 

sde780... on my ej8 you cant access either of the o2 sensor from the top... what you got? If it was only $70 you must have got the universal one where you have to cut instead of plug n play. Did it make your cel go away? Have you noticed a dif in gas mileage or anything?