Do we NEED a tune for a CAI? 5.4

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briandye

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So I had some money burning a hole in my pocket in my PayPal account, as well as an eBay discount code. I recently had a Magnaflow Muffler put on, which I love, but it’s too quiet. Figured a “CAI” might improve the sound a bit, by ditching the ridiculous chambered stock intake tube.

The factory intake is already a cold air intake, so I was just buying this strictly for improved aesthetics, and the sound.

Found one of the generic ones for about $60 with an aluminum(?) intake tube, nice thick rubber couplers, nice looking beefy chrome clamps, red filter and the “box” to keep it from sucking the hot engine air in.

I installed it, went fairly smooth. Everything was tight, every coupler sealed. No chance of air getting in past the filter.

Now I originally forgot to disconnect the battery before my first drive. Definitely felt a difference right away, but between shifts, the RPMs would flare. Not bad, but it did.

Took it home, disconnected the battery for about 20~ minutes, reconnected it, started it and let it idle with nothing on for 10-15 minutes. Idle was a bit rough at first, but smoothed out very fast.

Drove it around, the first few takeoffs it still flared, but then by the third time, no more flare. Definitely had better throttle response. A lot more “peppy” feeling. Sounded great as well. Got some food, went home and went to bed.

Got up for work, drove about 3 miles to the highway, and as soon as I turned on the entrance ramp, CEL comes on. Checked it right away with my WiFi OBDII adapter - Bank 1 and 2 lean.

Drove to work and home fine. Had to make a stop but I was close to home. Got back in, and the flares came back. But they were so bad the truck would stay in neutral basically when it went to shift and the RPMs would just jump up. I would have the feather off the throttle until it shifted. It was not happy.

It’s currently sitting in the driveway with the battery disconnected, and the stock intake re-installed.

Before you jump to say “that’s because it was a cheap no-name”, what’s the difference? It’s a tube that takes air from a large cone filter (which the filter I can see being vastly different); and houses the MAF sensor.

Is this expected, because I need to buy a tuner and custom tune? Or was this just an awful bit of luck?

The ironic part is, when I was cleaning the engine bay a couple weeks back, I removed the stock intake tube to really scrub it. The rubber “fitting” that slides over the throttle body side was folded in, and there was a gap big enough for a finger to slide through. Tons of unregistered air going in the engine but never noticed any performance loss or issue. Never a CEL either.
 

J Ski

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So I had some money burning a hole in my pocket in my PayPal account, as well as an eBay discount code. I recently had a Magnaflow Muffler put on, which I love, but it’s too quiet. Figured a “CAI” might improve the sound a bit, by ditching the ridiculous chambered stock intake tube.

The factory intake is already a cold air intake, so I was just buying this strictly for improved aesthetics, and the sound.

Found one of the generic ones for about $60 with an aluminum(?) intake tube, nice thick rubber couplers, nice looking beefy chrome clamps, red filter and the “box” to keep it from sucking the hot engine air in.

I installed it, went fairly smooth. Everything was tight, every coupler sealed. No chance of air getting in past the filter.

Now I originally forgot to disconnect the battery before my first drive. Definitely felt a difference right away, but between shifts, the RPMs would flare. Not bad, but it did.

Took it home, disconnected the battery for about 20~ minutes, reconnected it, started it and let it idle with nothing on for 10-15 minutes. Idle was a bit rough at first, but smoothed out very fast.

Drove it around, the first few takeoffs it still flared, but then by the third time, no more flare. Definitely had better throttle response. A lot more “peppy” feeling. Sounded great as well. Got some food, went home and went to bed.

Got up for work, drove about 3 miles to the highway, and as soon as I turned on the entrance ramp, CEL comes on. Checked it right away with my WiFi OBDII adapter - Bank 1 and 2 lean.

Drove to work and home fine. Had to make a stop but I was close to home. Got back in, and the flares came back. But they were so bad the truck would stay in neutral basically when it went to shift and the RPMs would just jump up. I would have the feather off the throttle until it shifted. It was not happy.

It’s currently sitting in the driveway with the battery disconnected, and the stock intake re-installed.

Before you jump to say “that’s because it was a cheap no-name”, what’s the difference? It’s a tube that takes air from a large cone filter (which the filter I can see being vastly different); and houses the MAF sensor.

Is this expected, because I need to buy a tuner and custom tune? Or was this just an awful bit of luck?

The ironic part is, when I was cleaning the engine bay a couple weeks back, I removed the stock intake tube to really scrub it. The rubber “fitting” that slides over the throttle body side was folded in, and there was a gap big enough for a finger to slide through. Tons of unregistered air going in the engine but never noticed any performance loss or issue. Never a CEL either.

Need to reset the fuel trims correctly, check out how to relearn fuel trims by makuloco below. Follow this strictly step by step and keep a time watch for accurate times


Your lean bc the engine is getting all that extra air and the computer thinks it only needs a little gas. Resetting fuel trims and air to fuel ratios should do the trick. No tune needed
 

AllBoostNoEco

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Do the 5.4s use a small MAF sensor to measure airflow or a full-diameter?
On my 5.0 F-150, it used a sensor that slides in to the tube, so if the tube was a bigger diameter than stock, then the proportion of air the sensor is measuring is wrong and the truck runs lean because it thinks it’s getting less air than it actually is.
 
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briandye

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Need to reset the fuel trims correctly, check out how to relearn fuel trims by makuloco below. Follow this strictly step by step and keep a time watch for accurate times


Your lean bc the engine is getting all that extra air and the computer thinks it only needs a little gas. Resetting fuel trims and air to fuel ratios should do the trick. No tune needed

I’ll give that a shot tomorrow, I didn’t know it was more involved than simply disconnecting the battery. Thanks! (I’ll post back results either way)

Do the 5.4s use a small MAF sensor to measure airflow or a full-diameter?
On my 5.0 F-150, it used a sensor that slides in to the tube, so if the tube was a bigger diameter than stock, then the proportion of air the sensor is measuring is wrong and the truck runs lean because it thinks it’s getting less air than it actually is.

It’s a flat, rectangular sensor, the same as any vehicle I’ve ever had. I can see what you mean by it not being able to measure all the air.

Now that I think of it, there was this black plastic piece for that area of the intake tube that I took out because I thought it was some sort of shipping protection or something. Maybe that will fix the issue.

I’ve driven a couple hundred miles since returning to stock, I gotta say I really miss the pep it gave the truck. I feel like I really have to give it twice the throttle for the same performance. Feels so restricted.
 
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briandye

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I forgot to snag a picture of that little piece I didn’t install last time, that kind of “cones” the MAF sensor.

It takes the large opening (4” I think?) and brings it down to maybe 3-3.5” where the MAF sits.

I disconnected the battery, as well as jumped the positive and negative terminals to drain that capacitors.

I’m currently sitting in it while it idles, doing the 19 minute idle part, and already notice a tremendously smoother idle. When I did this (the wrong way) last time, the idle as really shaky at this point.

I’ll post back in an hour or two, I have some driving to do, a good 50 or so miles, which it only took 10~ last time to kick the CEL on.

Thanks for your guys’ help so far!
 
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briandye

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So, drove about 75 miles, stop and go and a lot of highway. No issues. No pending codes, all systems are good! Didn’t flare one time even while relearning the shifts.
 

AllBoostNoEco

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Glad you got it sorted out. I’m sure it’s a lot more fun now.
 

sjwelds

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Need to reset the fuel trims correctly, check out how to relearn fuel trims by makuloco below. Follow this strictly step by step and keep a time watch for accurate times


Your lean bc the engine is getting all that extra air and the computer thinks it only needs a little gas. Resetting fuel trims and air to fuel ratios should do the trick. No tune needed
Can someone tell me what the exact title of this video is? For some reason I can't see it on my computer. Thanks in advance.

Edit: Never mind, got it to show.
 
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