Really bad fuel economy

[chickenleggs]

Hello all who have greater knowledge than me on the subject of Suby.

I have a 95 standard legacy wagon, EJ22 engine, Im getting really bad fuel economy and not from driving it hard, general cruising gets me maybe 350km on a full tank.

Extra story bits, i have a CEL on which is the fun p0325 Knock sensor code,

The car sat for a year before i got it, could the injectors be dead or dieing?

 

I have replaced oil and fuel filters, engine oil and tranny fluid, new plugs

 

Any ideas to increase economy would be greatly appreciated

I dont want to if i dont have to

[cal_look_zero]

Well start with replacing the knock sensor.

 

Then check the PCV on the intake manifold.

 

Replace plugs, wires, and fuel filter.

 

And run a can of Seafoam through it.

 

All told, less than $100 and 1/2 an afternoon.

 

Sounds like it just needs a little maintenance, and a little "How's your father?" to clear out the crud.

[chickenleggs]

Thanks for the help, ill let you know how it goes, muchly appreciated

[Ricearu]

the knock sensor lets the ecu know exactly how far one can advance timing. If the knock sensor is out, it will run at a known safe ignition timing map. This sucks because efficiency goes up as it approaches tdc. My old leggy went from 18mpg up to 24mpg with a new knock sensor. but it was a 90 (no obd)

[chickenleggs]

Thanks for the reply, new knock sensor is going in tomorrow and some seafoam, then we wait and see what happens.

[Olnick]

Don't forget plugs (most basic NGK coppers) , wires (must be OEM or NGK--don't waste your money on parts store cheapies), fuel & air filters.

[mikaleda]

a tune up might not be a bad idea if the seafoam and knock sensor doesn't fix it. The better the plugs and wires the better the fuel economy i always use beldin 7mm max life wires (napa lifetime) when i can its worth the extra money.

 

oh and if all else fails check your catalytic converter it might be plugged.

Edited June 1, 2012 by mikaleda

[ivans imports]

the bigest cause of bad milage i see is from miss matched tire preshure very picky standard is worse 35 psi front and 32 psi rear to compensate for engine wheght. A ten psi differance will pull your milage down also no exhaust leaks at all any leaks = bad milage mabee o2 senser