Eddy G

Hi last month had MAF sensor replaced car kept cutting out, now noise coming from engine and looks like im going to have to have rebuild, faulty MAF sensor to blame? How can i stop this from happening again i can't believe that there is nothing in the engine management to stop lean running. I've heard a knocklink sensor can tell if there is detting but i gather it works from detecting engine noise is that good enough to tell wether your MAF is screwed and your engine is eating itself.I'm pi**ed that a faulty sensor can cause so much damage.
What mods are essential to stop this happening again
1997 wrx import decat and induction kit.
P.s. i love the car enough to keep it going and going

dij

Hmm interesting opinion.

I notice you have an import .What fuel where you using ?did it have a remap?
What safety features did you have?

IMO:
Its total bullox to have a part that costs £73 but is responsible for a £3000+(approx) part.
And yes why the f##k dosent the engine light flash or stay illuminated when the MAF has failed.Perhaps there should be seperate warning light with 'MAF'
written on it to warn you that its time to get it changed.
It is anoying that the engine seems to run perfectly and feel great,without giving you any warning its about to s41t itself.
Maybe no one at Subaru gave a s41t or did they not know.

Fortunately a knocklink is available which can warn you of detting,so that you can let off the gas and start driving it like a corolla.
Sorry to hear about your car.
Im sure there is many who can help you on this.

Try David at API engine centre for the rebuild/replacement,im getting mine done from him too.

redeye

iv heard a lot of talk about maf sensors,now i know what they are,know what they can do if not working properly but do you have to get them checked or change them at any specific time?

dij

Some body please tell me im wrong

Eddy G

dij yeahh a bit short on safety features i've learnt my lesson run it on optimax and OB so theoretically the car should think its running on nice jap fuel. I think i will have to get some sensors and a remap ouch more mullar...

The_Judge

As a rule of thumb, an import should have its ECU remapped to suit UK fuel. This saves fannying about with octane booster, and is probably the best way to protect the engine in the long run.

Yes you can buy lots of gizmos to tell you what's going on, but they won't prevent problems. That's still down to the driver, making it a risky alternative.

Knocklinks should be the first purchase for ANY Impreza in my opinion, whether UK, JDM, standard, or modified. AFR/boost/EGT/oil pressure/oil temp/etc gauges are useful for modified cars, depending on level of modification. Cars that do track days should take extra care.

MAF sensors should ideally be replaced every year (or sooner), but as previously stated, aren't included in the service schedule, and don't trigger a CEL unless they're totally shagged. Again, it's down to the owner to be responsible. Owners with upgraded induction should keep an extra eye on them.

Lambdas sensors should also be changed regularly, but the consequences of not changing them aren't catastrophic.

dij

Why would the lambda fail?

Could it be conytaminated with oil?

possibly the first signs of turbo seels or piston rings?

Isnt it possibble to clean the lamda sensor with brake cleaner?

They must be more resiliant than the maf,as they are designed to withstand so much heat and exhaust fumes?


So it is true to say that you should get your hands on a new muff as regularly as possible?

The_Judge

Over time, they get coated in crap from the exhaust gas.

Possibly, if your engine isn't very healthy. But not air filter oil!

When mine went, I tried that, but the crap that was on it was seriously caked on. Left it to soak in a cup of brake cleaner, but no joy.

Yes they're more resilient, but you're not really comparing like for like. If the lambda was in the MAF's location, it would probably last forever. If the MAF was in the lambda's location, it wouldn't last 5 minutes.

I try to, not always successfully though...