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**phil2cool** · 07-02-2008, 09:55 PM

For the past year I have been procrastinating on getting my check engine light fixed. I couldn't clear a P0171 lean code. It occurred right after installing a K&N cai. I was stubborn and really wanted my cai to work. So I never put the stock intake back on. Only negative thing that was different was that my fuel millage had been reduced

I started to work at trying to clear this code this last weekend. I installed a new fuel filter, o2 sensor, and spark plugs (shortened life from running rich). None of those worked. A mechanic said all sensors were reading ok. I didn't get specific numbers though. Originally I did test my MAF sensor to see if it was working. I did see a difference in engine performance without it. That led me to assume it was working.

On a roll with this recent motivation I decided to go at what caused this problem in the first place. I didn't have the stock air intake nearby. So I came up with the idea to restrict air flow. My theory was based off of the engine thinking it had to much air. I went to the recycle bin and pulled out one of the cardboard flyers that I get from junk mail. I wrapped it around half of the air filter cone. I started up engine and code was gone. One year of this crap and it was solved by some cardboard! I did notice my performance has gone done a lot, almost to stock levels. For the interim I might keep reducing the paper until I get the check engine light again.

I see people on these forums get cai to work all the time. Is my MAF sensor bad because it can't handle the higher volume of air? Would repalcing it with a OEM sensor solve my problem? Or would an aftermarket MAF sensor fix this issue? I don't necessarily want to get a tune either.

07-02-2008, 09:55 PM	#1
phil2cool Rookie Join Date: Jan 2007 Posts: 27	K&N FIPK maf lean code solution? For the past year I have been procrastinating on getting my check engine light fixed. I couldn't clear a P0171 lean code. It occurred right after installing a K&N cai. I was stubborn and really wanted my cai to work. So I never put the stock intake back on. Only negative thing that was different was that my fuel millage had been reduced I started to work at trying to clear this code this last weekend. I installed a new fuel filter, o2 sensor, and spark plugs (shortened life from running rich). None of those worked. A mechanic said all sensors were reading ok. I didn't get specific numbers though. Originally I did test my MAF sensor to see if it was working. I did see a difference in engine performance without it. That led me to assume it was working. On a roll with this recent motivation I decided to go at what caused this problem in the first place. I didn't have the stock air intake nearby. So I came up with the idea to restrict air flow. My theory was based off of the engine thinking it had to much air. I went to the recycle bin and pulled out one of the cardboard flyers that I get from junk mail. I wrapped it around half of the air filter cone. I started up engine and code was gone. One year of this crap and it was solved by some cardboard! I did notice my performance has gone done a lot, almost to stock levels. For the interim I might keep reducing the paper until I get the check engine light again. I see people on these forums get cai to work all the time. Is my MAF sensor bad because it can't handle the higher volume of air? Would repalcing it with a OEM sensor solve my problem? Or would an aftermarket MAF sensor fix this issue? I don't necessarily want to get a tune either.