i have a problem with my intake

[FirstWHIP9gen]

well its not just one issue i have a rattle anytime i step on the gas my car idles rough and i checked the vacumm hose and all the couplers the are virgin tight i have everything done like the manual said and i still loss performance from stock airbox i just dont know what the issue is help please

[9Ggts]

If it just came out when you put the stock airbox back it could be the MAF sensor. If it is, I would spray it with electric/contact cleaner to clean it. Don't touch the sensor with bare hands.

[FirstWHIP9gen]

ok so far ive cleaned the MAF sensor with some MAF sensor cleaner and put back the stock airbox in it and hooked everything back like it was and it still have a bad idle sometimes it cuts off during idle so i think it might be the throttle body cause i drove it today and i couldnt go past 2500 rpm if i did it would bog down cause its running rich ass hell i found that out by smelling the exhaust and checking the spark plugs so what do u think is the problem .. and i found out its not a rattle its the sound of the air coming in sputtering wen accelerating

[9Ggts]

Did you drive it for a few miles? Sometimes it takes awhile for the ecu to relearn. No kinked vacuum hoses? You have a 4 cyl? Are your plug wires with coil packs?

[Gotti]

picture of the intake system would help. no CEL?

[Reelax]

clean throttle body. did you check for any intake manifold cracks? the 8G 14 manifolds are known to crack, might have happened to urs as well.

[FirstWHIP9gen]

so i found out the problem ..so i took it up to mitsubishi and they told me that my exhaust manifold must've gotten so hot that the material in the catalytic converter melted and gotten stuck in the downpipe and its really restricting the flow and i might have to change the 02 sensors as well ... they tried to tell me it was gonna be 3116.86 i said fuck no . i went to rock auto and i can get errthang for 600 and i can put it in my self