Professional Product Typhoon Intake Manifold

Hey Guys,

I am havin a NIGHTMARE with my f***ing car. I had the manifold break and i didn't want to install another :poo: plastic one so i bought this one. Now i am popping codes P0171 and P0174, lean system. Yes, i know there are sensor possibilities, injector issues, and what not, but before i jump down that rabbit hole, is it possible that this aftermarket manifold is making the computer read a lean mixture? i know it has more volume in it and pushes more air through the system, so my gut is telling me it is the damn manifold itself. Please let me know, soon.
 
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is it possible that this aftermarket manifold is making the computer read a lean mixture? i know it has more volume in it and pushes more air through the system, so my gut is telling me it is the damn manifold itself. Please let me know, soon.
IMO the answer to your question is no. The after market intake isn't pushing more air making the PCM "think" it's running lean. Why? Because your car is a MAF car. Any extra air going into the motor because of a new intake should be metered. Thus the PCM will "know" how much air is really going into the motor and "adjust" to match.

It's seems to me that your problem is related to the work done but not in the way you are thinking. There is an intake leak somewhere or the MAF is not reading correctly.

For the DIY'er finding vacuum leaks can be a challenge. Few of us have professional smoke machines. I have had great luck using a propane based wand to locate vacuum leaks. It's basically a long tube hooked to a propane bottle. I monitor the front O2 sensors while probing around for possible leak sources. When the motor sucks in the propane it will immediately show up as a change in the O2 sensors. There could be an RPM change as well.

Also don't ignore other less obviously vacuum leak sources. Examples:
  • The power brake vacuum booster (if equipped). In the off chance that the manifold has the power brake booster port has it been plugged and capped?
  • Is the fuel rail pressure sensor (FRPS) intake vacuum reference line connected and leak free?
  • The EVAP system
  • The PCV system
  • The EGR system. Is it connected and leak free?
  • Any unused vacuum ports. Are they plugged and capped?
Any exhaust leaks?

Have you checked the fuel pressure? A restricted fuel line can also cause a lean condition.

What about the gaskets? Especially between the intake and the head. Throttle body and intake?

Do you have an ODB2 scanner? If so, it would help to compare the MAF value to see if it's "reasonable".
 
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Is there any follow up? Did locate the issue? I have heard that sometimes the lower section has not been torqued and causing vacuum leaks.
I have just bought one of these intakes, waiting for delivery, and was wondering what happened to your car.
 
Is your a foxbody ?? Its kind of hard for it to mess up as bad as his . Make sure you know where all the lines go . You only have a few vacuum lines . He said plastic one meaning newer . I never worked on one of them but they seem more complex than the old 302.