Hyundai Repair: possible throttle body problem, air flow sensor, mass air flow sensor


Question
The aftermarket intake did not hook up to the mass airflow sensor. The modification I made to it was actually to include the stock shape so I could hook the air flow sensor.

The check engine light is NOT on. The problems I had before with the intake threw a check engine light on becasue we completely disconnected the mass air flow sensor and just let the plug dangle for about 3 months untill my car started to putter like a go cart at which point I put the original intake box back on untill I could figure out how to Modify the aftermarket intake. Basically I took out a senction of the aluminum tube and replaced it with the air flow sensor section from the stock intake. The car was running fine for a long while with the aftermarket MODIFYED intake. Should I put the stock intake box back on, or just replace the mass airflow sensor? If so is there a reason I cant put aftermarket intakes on?
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The text above is a follow-up to ...

-----Question-----
I have a 2001 tiburon. I have an aftermarket cold air intake that is actually sucking in hot air becasue I had to modify it to fit, but for the past month or so the car seems to jump foward and backwards when I let off the accelerator and put my foot back on. I thought it might be spark plugs and wires, so I replaced those and just recently got an oil change and the problem stopped for about a day or two, but it continues to happen. When im at high speeds the car runs decent, it is usually only at low speeds or mainly when i take my foot off acelerator and reapply it.Im not sure if its the aftermarket intake, or a new throttle body, or if I just need to clean the throttlebosy and throttlebody plates. What do you think?
-----Answer-----
It sounds like an air flow sensor problem.  Check the air flow sensor and make sure the wires aren't rubbing anywhere.  Make sure there are no leaks between the air flow sensor and the throttle body.  Make sure the air flow sensor is installed with the proper orientation (arrow pointing toward throttle body).

Any chance the check engine lamp is on?


Answer
You might try it with the stock intake to see if there's any change.  

You shouldn't replace the air flow sensor unless you actually determine that's the issue.  Over the internet, I doubt I'll be able to do enough diagnosis on your probem to make my opinion worth the expense of purchasing a part and replacing it.  Since your check engine lamp is not on, it'll probably take a professional actually feeling the problem and looking at the engine data as it occurs.  It could turn out to be something like the fuel pump.

As long as the air flow sensor is installed correctly and the tubing has no leaks, there's no reason you cannot install an aftermarket intake.  There can be some negative consequences, however.  Most of the filters usually do much less filtering than the factory filter, which can result in a decrease in engine life expectancy.