Civic shoddy gas mileage?

[mowglee]

My friend has got a 96 Civic Si with approximately 160 k on it. He is only getting 240-250 km out of 30 L? Is this normal ?

[GQBalla]

no, i get over double that on 30 l of gas.

try a tune up

*edit

also depends greatly on how he drives, if hes ripping it all the time i could see him gettin that much

[HHURICANE1]

Could be a dead/dying o2 sensor as well. Most people don't change them until the CEL comes on but just like spark plugs they are a tune up item. Will definitely affect mileage.

[mowglee]

Originally posted by HHURICANE1
Could be a dead/dying o2 sensor as well. Most people don't change them until the CEL comes on but just like spark plugs they are a tune up item. Will definitely affect mileage.


Which o2 sensor? Upper or lower? both? He doesn't bag on it shifts around 3 k?

[Mr_ET]

is he feeling any loss in power?

I would also guess it's an o2 problem. They are unfortunatly a bit expensive but he can try changing one and see if anything improves, if that changes nothing he can then swap the good one into the other 02 slot and reuse the previous one taken out and see if that helps.

The wires should reach and it's a good way of testing both without spending the money on both right away.

If performance is affected and it feels sluggish I would look at the spark plugs, wires, dizzy, fuel injectors and fuel filter.

[revelations]

Has this been going on for a long time or did it start all of a sudden?
Does it burn oil?
Have the plugs and airfilter been recently checked/changed?
Any check engine lights?
What type of gas? (87 or high octane)
Tires inflated to recommended pressure?
Tires wearing in evenly?
Automatic or manual?
Any mods to the engine/exhaust?

[mowglee]

Originally posted by revelations
Has this been going on for a long time or did it start all of a sudden? recently
Does it burn oil? none
Have the plugs and airfilter been recently checked/changed? 5000 k ago
Any check engine lights? none
What type of gas? (87 or high octane) regular
Tires inflated to recommended pressure? yes
Tires wearing in evenly? yes
Automatic or manual? manual
Any mods to the engine/exhaust? all stock

[HHURICANE1]

It would likely be the upstream as that is the one that affects the fuel mixture most. It is also the one that wears out the most.

[EFHatch]

My guess is a faulty o2 sensor, and the primary, or first one will be the one that needs replacing.

You can find NTK O2 sensors (original manufacturer for Honda OEM) for under 100.00 and very simple to replace.

[Mr_ET]

OP ^ he can help you get that part also if need be, great guy to deal with!

[cyrusli]

Could be that the fuel filter needs replacing.

[el-nino]

It might be your cat. This happened to my EL and I just replaced the Cat and everything was much better!

[benz_890]

primary 02 sensor