Hey guys im new here and dont quite know how things work but i want to post a question about a problem im having.. Just put a cold air intake on my 99 f150 with a 4.6. its a CAI with a 4" tube and its not an oiled filter. there is NO vacuum leaks, the mass air flow sensor is clean. im getting the codes 171 and 174 now and i know its from the intake because thats when it started running lean. Is there any way or anything i can adjust to fix this other than buying a 300 dollar programer?? if i take it to a ford mechanic will he be able to fix this? ANY suggestions will help PLEASE.

 

Sigh...

Put the old intake back on...

 

That would be my solution.

 

lol i knew i would get that reply from this question. the main reason i put it on was because the previous owner had totally destroyed (so i thought) the stock intake. The air box was cut off and he had one of those cone filters ghetto attached to it with a hose clamp and some duct tape. Its sad that thing even worked! I assume its the bigger intake tube causing my problems. The truck adles great and runs good except for at high rpm sometime it feels like its losing power, like its starving for gas gas almost. I changed fuel filter. Im trying to avoid buying a PRICY stock intake.
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Basically I want to try anything possible to avoid puting that stock intake back on. The truck actually runs better than it did before, better throttle response and it sound great I just dont want to burn something up by running it lean.

 

Factory sized/style intake or tuner, that is all...

 

The factory system has been engineered to work over the whole RPM range.
What you have now does not.
The Mass Air meter is seeing a flow path alteration through it and changing it's output signal.
The codes are telling you the PCM sees a signal 'represenative' of to little or to much air for the RPM and TPS angle/load indication.
This ends up making a large change to the fuel tables to the point they range out of limits.
This is when the codes are set to tell of the condition that caused it.
The air meter samples an engineered percentage of airflow to get the signal within spec, the PCM uses.
The deal you have now has upset that relationship.
The design intent is for general use not peak power and hot roddiing.
This is where owners can get into issues trying to change the stock design.
the, the , this, the etc.
Good luck.

 

thanks for the insight bluegrass that was an awesome explanation!..

after TONS of research i FINALLY solved the problem or at least made it a lot better! I read an article in JEGS on EFI and how everything works to get a better understanding. The stock position of the MAF was not a factor because there was no "bend" in the intake BEFORE the MAF. Now that there is a bend before the sensor the position is EVERYTHING i had the actual sensor in the stock location (facing the front of the truck) But with the aftermarket intake that put it on the inside or the short side of the intake tubing where all main airflow runs on the outside, or the long sweeping side of the intake. Makes perfect sense. so i turned the MAF so that it is now on the other side of the intake giving it a solid reading.. that was one part of my two part solution

2. I noticed all chevy and some fords have a screen before the MAF. stock f150's dont. what the screen does is eliminate the erratic air going through the intake as it passes through the MAF. (this may sound rigged but its not and its looks factory) I actually cut a window screen to side and clamped it in between the MAF and the MAF plate adapter cold air intakes require. WORKED PERFECT!! and looks like it came that way. So i dont know if the positioning worked or the screen worked or a combination of both but my truck runs better than it ever has and no check engine light! thought i would post this for those out there who cant help themselves and have to have a CAI LOL. thank you all for the input. hope i can help somebody out there
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Very good.
Glad you searched it out.
Not knowing what you have, I could not give any pointers on what to do..
Good luck.

 

thank you! and by the way this forum rocks
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Oh, btw, what brand/style of CAI did you buy? Just so everyone knows..

 

actually it was one of those cheap ones off of ebay. like 70 bucks. the fit was surprisingly good and it looks nice too. The only problem with these cheap ones is they dont research and test how they work just how they fit. on something like a k&n intake (which is 3 times the money) the air fitter is directly off the MAF so theres no bend before the MAF causing erratic flow to throwing the bad reading. if somebody were to do everything i did with a the off brand intake i would recommend one over a k&n just because of the price. It actually puts the air filter further away from the engine heat than a k&n would too. RUNS GREAT!