K&N MAF Problem--awful mileage--Please Help!!

[goser]

I've installed a K&N stock replacement air filter in my 98, and my mileage has become horrible. I'm reading code P0103 (Mass circuit high input) and don't know how to fix this. Everyone seems to agree a K&N will help mileage, but it's cut mine in half. I've cleaned the MAF wires, but don't think the MAF is defective; it just doesn't like the K&N. I can't seem to find a solution--others online have said everything from disconnecting the battery for 15 min to reset the ECM, to replacing or just unplugging the MAF. (Is that really a good idea?) Anyway, I'm just about ready to go back to paper filters unless someone has a solution!

Thanks,
Happy Holidays,
L.

[Crasen]

The only time I have heard of a K&N air filter causeing a MAF problem is when they are cleaned and someone sprays too much oil on it and then installs it, the oil then covers the mass airflow sensor, if you put a paper filter back in and the problem persists then I would check voltage at the plug for the MAF sensor, I believe it should have a 5 volt reference voltage

[dmbrisket 51]

high input means you have a real problem! its not the filter, most likly. K&n's cause a lot of problems on our trucks, some are lucky and have no problems and others get a basket case out of it, i was lucky and have no problems with mine (knocks on wood) and if you live in the salt belt, during the cold months, a cold air intake (or high flow) does no good and harms gas mileage

[Spyderdan]

So dmbrisket If I purchased the K&N Fipk i should remove it in the winter and put the stock intake back on?

[dmbrisket 51]

well where do you live? if your in the northern snowy/cold states, yes, in the south no, winter grade gasoline is not as good as summer grade gas where it gets cold and this reduces fuel efficency already, and its cold air going into your moter in the winter anywayse

[tstewart]

Originally Posted by dmbrisket 51

well where do you live? if your in the northern snowy/cold states, yes, in the south no, winter grade gasoline is not as good as summer grade gas where it gets cold and this reduces fuel efficency already, and its cold air going into your moter in the winter anywayse

How can a K&N or any airfilter affect the engine performance in the winter month? The air temperature to the motor will be the same regardless of the filter type. The quantity of air into the motor is basicly constant based on the motor revolution since the motor is a constant discplacement.

I have been using a stock type K&N for 3 years with no problems. I have had reduction in milage during the winter months with both filters. It is not the filter but a combination of temperature, related fuel mixtures, additional friction in greased components etc.

[MT-2500]

If it is giving you that much trouble and the code will not clear you might as well replace the maf sensor or check the wiring real close.
Put a OEM filter back and see what it does.
The main problem on a K&N filter is the oil in them gets into the maf and other sensors.
The newer the truck the more it will affect it.
Was the one you put in well oiled or dry?
Was it just a drop in or a cold air intake setup.
Is the air intake hoses good and tight.
If you have a good scanner I can post some test for that code if it would help you.
MT

[corning_d3]

Did ya break off the little resistors when you were cleaning that MAF?

[goser]

Originally Posted by MT-2500

If it is giving you that much trouble and the code will not clear you might as well replace the maf sensor or check the wiring real close.
Put a OEM filter back and see what it does.
The main problem on a K&N filter is the oil in them gets into the maf and other sensors.
The newer the truck the more it will affect it.
Was the one you put in well oiled or dry?
Was it just a drop in or a cold air intake setup.
Is the air intake hoses good and tight.
If you have a good scanner I can post some test for that code if it would help you.
MT

Yeah, I'm going to stick the paper filter back in with the next tank to see. Oddly enough, it seems to have gotten better since I cleared the code--that's just a guestimation at this point though.--and luckily the code hasn't reappeared since.

It was just a drop-in filter, brand new; factory oiled. All the hoses are tight. Unfortunately I was just borrowing a code reader, but thanks for the offer.

dmbrisket, do you mean a real problem like a pooched MAF or should I be looking for bigger problems?

Guess i'll wait and see (and hope)

[dmbrisket 51]

Originally Posted by tstewart

How can a K&N or any airfilter affect the engine performance in the winter month? The air temperature to the motor will be the same regardless of the filter type. The quantity of air into the motor is basicly constant based on the motor revolution since the motor is a constant discplacement.

I have been using a stock type K&N for 3 years with no problems. I have had reduction in milage during the winter months with both filters. It is not the filter but a combination of temperature, related fuel mixtures, additional friction in greased components etc.

no, cold air is more dence, so you lean the moter out, the less restrictive higher volume air filters make the ingen work less to get the same amount of air into it, so yes displacement stays the same, how hard it has to work for that air changes, and the dencity of the air changes with cooler temperatures, and i dont know if i did or didn't but i have been using a cold air intake for over a year and it never gave me a problem, but on some chevys and almost all fords (mopar is pretty good, no codes from them) with 'better then oe' filters set codes, and play hell in the winter, it is not what the computer was set up to run with, its like a simple rv cam can shut down a sefi v 8, but you can make a carb go potato potato, without any running issues, vaccume is another story