Aftermarket Mass Air Flow Sensors (Jet and Granatelli)

Discussion in 'Performance & Fuel' started by mjalstad, Jan 21, 2009.

  1. mjalstad

    mjalstad Rockstar 100 Posts

    So even though I was very skeptic about aftermarket MAFs I kept hearing a lot of good things about HP and MPG increases when using them. I bought a used Granatelli online but before I even got it I started hearing better things about the JET so I bought one of those online also. I got it from a guy on ebay who said his broke and he got a replacement one but changed his setup and couldn't use it anymore so it was never even used.

    I bought my truck just about a month ago and the only thing I had done to it was put a Hypertech programmer on it. I monitored the long term fuel trims and found that my truck was running a little lean but not too bad, an average fuel trim of about +9%. I put the Jet Maf on and could definately tell that there was a power increase with it but after a few days I noticed the check engine light had come on. It turned out that it had come on because of a lean condition, so I monitored the fuel trims and they were about +20-25% with the MAF. Today I got some MAF cleaner and cleaned the MAF as well as installed a Volant CAI with the ram air scoop and uninstalled my Hypertech so that I wouldn't have increased timing while running lean. On my way to work today the fuel trims are a little better, around +15-20% but still a lot higher than I would like. Is this a common problem with the aftermarket MAFs?

    I got the Granatelli in the mail which I have up for sale on ebay and boy oh boy did it look cheap. The Jet one looks alot better, it appears Jet removes the honeycomb and cuts some holes in the bar going across the middle for a smooth professional look. The Granatelli does not look like something I want to put in my truck, the honeycomb and the bar going across the middle are removed and the black plastic bar going across is cut down as far as possible, making the sensor wires supported by a lot less.

    Anyways, I think both of them are going on ebay, but has anybody else had problems like this? I'm sure a lot of people think they add HP and MPG which they do because your truck is running so lean but it is not the way I want my truck to run and how can they sell a product that makes your check engine light come on?
  2. 04sierracrewcab

    04sierracrewcab Epic Member 5+ Years 1000 Posts

    Never heard of this.

    Maybe somone else has had this problem.
  3. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    I guess i never saw the point in a high dollar MAFS, your computer will automatically readjust the levels when it gets more air coming in the intake with a higher flowing air filter, will it not. And if the cumputer cant, a custom tune would make up for it wouldnt it, maybe i am wrong.
  4. MWright936

    MWright936 Epic Member 5+ Years 1000 Posts

    That's always been my logic. It may be wrong though, I dunno.
  5. Cody115

    Cody115 Rockstar

    Yea I agree with you. There is no point in selling your Jet MAF. All you need done is a custom tune and they will notice its running lean and compensate for it. Plus you will get added hp and mpg so why not spend the few hundred?
  6. mjalstad

    mjalstad Rockstar 100 Posts

    The computer will make up for the added fuel, but only to a point. That point is 25%. So if my LTFT's are at 25%, that means they really should be higher and whatever that difference is is how lean it is running. I suppose a custom tune with it would probably be the way to go but that's too expensive. I just bought a DiabloSport Predator, I can adjust my fueling with that right? Or will that only do WOT fueling? My last car was a modified Grand Prix GTP and I had custom tuning software for it and I really liked that but it only cost me about $350 and it was very neccessary due to the mods that I had done where everything I've seen for my truck would be at least $500 and I don't really plan on doing anything that will neccessitate (Is that a word?) that.
  7. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    nelsonperormance is 275 i think or try his nale has been popping up on here alot lately and is very cheap
  8. Tampa Tuning

    Tampa Tuning New Member

    The granatelli are junk. Had it and return it. The unscreen gives a little better pick up preformance off a light but lost some parking lot driving.

    I upgraded with a 85mm MAF, then rescaled to with my HP Tuners program.
    Last edited by a moderator: Sep 8, 2011

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