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Discussion Starter · #1 ·
Is it bad that I’m getting worst miles per gallon with a cold air intake then the factory intake.... 2008 Hyundai tiburon GT v6
 

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2006 Hyundai Tiburon SE
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Yes that is bad. Did you reset the ECM after installing? Do you have a check engine light at all? If so, read the codes and share them please. What do your LTFTs show on the OBD2 live data? Which CAI kit did you install? Have pics?

Normally on an 08 ECM you would see lean codes and a slightly extended MPG compared to stock.

Unfortunately you own the car that doesn't accept modifications very well. The ECM in 05+ and again in 07+ started pulling fuel out of the tune for emissions and MPG improvement. This means that adding a CAI or other breathability mods will cause you more grief unless you can mitigate it. A good work around is to swap your ECM for a 04 ECM with the Z4, Z8 or ZC sticker on the ECM plug. The early 4mbit ECMs take modifications well without going lean.
 

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Discussion Starter · #3 ·
It’s reading that MAF needs to be replaced but I just installed a new one last month ... even tho I replaced it . There is still a check engine light and it’s reading that engine is to lean ... now I do have an exhaust leak in the flex pipe ... I have a full exhaust kit from headers-mid pipe- and catback sitting on my living room just waiting to get installed by shop. But would that exhaust leak cause it to be lean? @chase206
 

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When we ask for CELs we want the exact code you received for it to be helpful. There are dozens of different codes relating to MAF and lean conditions all caused by different issues.

What brand MAF did you replace it with? If it wasn't a genuine Hyundai or Siemens branded part, throw it in the garbage and buy a proper MAF sensor. The MAF is critical.in calculating your AFR and should cost you no less than $150 for the correct part.

Depending on the location of the exhaust leak, it could give your ECM a false positive for a lean condition and dump more fuel. The exhaust leak would have to be near your upstream O2 sensors for that to happen. A leak in the catback would have no effect on your AFR. A leak in the flex pipe is too far downstream to affect your AFR. It should be assumed that you MAF or CAI is causing your lean condition.

Can we see a picture of your CAI and how your MAF is positioned in the pipe? The distance between your cone filter and the MAF can cause problems for your MAF reading accurately.
 
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Discussion Starter · #5 ·
The flex Pipe exhaust leak it cause the engine to shake allot and it sounds like a v8 with cams and hold on I’m going to autozone to get the obd2 codes @chase206
136618
 

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The CAI looks good. You may want to rotate the MAF so the square part is facing up and as level as you can. What brand is the MAF though? It should have a holographic Hyundai sticker on the square part if it was a genuine Hyundai component. If you look inside of the MAF do you see two thin parallel strips of metal? or two blue/black blobs that look like resistors/thermistors? The low quality MAFs have the blue/black blogs and aren't accurate enough for our ECMs AFR algorithms.
 

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Discussion Starter · #7 ·
The maf was a MOSTPLUS from Amazon . The one that was already in there had a little blue piece in the middle... the one that’s in there now just is all black with a two thin metal piece in the middle. Here’s a screen shot @chase206
136619
 

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Oh and @chase206 what if I bypass the mass air flow sensor for the cold air intake? Will I gain something or is that bad
You won't gain anything. Your car will be in constant open loop mode without the MAF and your AFR will be all over the place. The MAF is a very important part of the AFR calculations to deliver the right amount of fuel. Without it, you'll dump too much fuel and lose MPG.
 

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I agree with everything said except a leak in your flex pipe will cause a lean code... I had a leak in my flex pipe and got lean codes every half a hour.. once I got the flex pipe fixed no more lean code..
the down stream o2 sensor will send that code..

but yes if it sound like a cammed v8 get a new mass air flow, quick way to tell if she’s shot if it had trouble idleing unplug it and it should idle mint... but don’t drive like that it’ll mess **** up
 
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