Summary of Mods:

Megan Racing TP's with defoulers
K&N intake

I was doing a WOT shift at 5500rpm in an attempt to catch up to traffic, and all of a sudden, boom, limp mode it felt like. When I pressed the gas it barely went anywhere and just sputtered and stuttered.

I thought it was a bad tank of gas, and gave it new gas and reset the ECU, it did indeed get better, but now there is still hesitation in acceleration, and now a neat new issue:

When I press in the clutch and coast, about half the time my car will just die. The RPMs drop, and drop, until they hit 0.

Any ideas guys?

 

never had this happen, any codes...
maybe maf sensor

 

Dude the same thing happened to me couple weeks ago. Checked for codes, even tho i didn't get the SES light it still showed the code P0327, Knock sensor low input. So im guessing it's one of your sensors.

 

It threw 2 codes:P0171 and P0174, bank 1 and 2 are lean.

I'm thinking fuel filter?

heres what the manual says:
1st - If bank one and two codes set together suspect fuel pressure or MAF Sensor
2nd - Oxygen sensor defective
3rd - Ignition misfire or vacuum leak repair
4th - Fuel ignition problem.

MAF looks a bit dirty, but isn't bad (it wouldn't suddenly turn to crap)

 

Issue resolved, was the MAF.