Can A Dirty Maf Sensor Cause Knock And A CEL? i was changing the oil on the evo the other day and i was cheap last change and put castrol oil very dumb and i went to buy some mobil 1 and i took off the maf sensor and cleaned it as much as i could with a rag but can it cause knock and a cel cause i was getting it for the longest and know that i did all this no knock and no cel?

 

not sure exactly what that last sentenence meant, but yes a dirty MAF can cause knock and a MIL (CEL). What codes did you pull exactly?

 

o i meant that since my tune for my new turbo ive been getting the cel knock and it was getting annoying and i got a cel the other day and i took it to my tuner and he said that my maf sensor was dirty to clean it and it would go away and i did and it went away and i dont get knock anymore ?

 

Did you just use a rag on it or did you clean it with a solvent? AutoZone has a can of MAF cleaner for about $6, it works pretty well. If you have an electronics store (not RadioShack) close to you, you can grab a bigger can of the same stuff for about half the price.

 

Never Heard of that fix before but if it works cool. In theory a MAF meters the amount of air and temperature of the air going in through the intake boot. So if its not metering the correct amount the engine computer won't always supply the correct amount of fuel into the combustion chamber. Basicly if its dirty computer thinks only X g/s are being sucked in and reality x+some more g/s are. So it supplies some less fuel than you need and you run leaner. Lean usualy= knock, this is all my basic therory that I twisted to fit your situation. But its probably completely wrong and someone will come in here and rip it to shreds. Also Just cause it says "Service engine soon" or "Check Engine" or your buddy calls it a "check engine light" Its refered to as a "Malfunction Indicator Lamp" MIL

 

O ok well ill see how long this lasts

yeah i just used a rag and a screwdriver to reach in

 

Woah you have to be carefull with that sensor. A screwdriver can easily damage the sensor. Id go with the electronics cleaner from an auto parts store.

 

I Wasent like stabbing the sensor just to push the rag in .....if i get it wet from the inside cant it get messed up?

 

Nope not if you use the right product. That electrical spray evaporates very fast.

 

ok so next time go to an auto parts store and get a spray can anyone be more specific i dont want to buy the wrong spray and end up buying a new sensor

 

thats what i did. works perfectly!