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Really bad fuel economy

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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 :horse: if i dont have to

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.

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)

  • Author

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

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.

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 by mikaleda

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

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