Ok, heres the problem. My car runs fine most of the time, but sometimes when driving it looses 50% power, like a lack of fuel.. I will be crusing in 3rd gear and I can feel the power drop, give it gas the rpms climb but not fast(like im in 5th gear)down shift to seconed and the same thing...I thought it might be a bad fuel pump so I changed it out, but still does it...It feels like the motor is being choked, when it happends..Fuel pres regulator has been changed also(OEM). I have a JDM H22a, I going to change the coil wensday to see if it cures the problem(coil has 180,000 miles on it) But I'm now thinking it might be the o2 senser....I also got a gergaling sound coming from my exhuast(when I downshift,and barely give it gas) like not all the fuel is getting burned(Exhaust tip covered in black soot) I can wipe the soot of the tip and drive 5 miles and it covered again...Dont know, help

 

try advancing your timing.

 

I was having a similar problem with my car, and it was the throttle body that was messed up. Is your engine light on? See what code it throws, and that should tell you the problem

 

have you messed with your cam settings at all before you encountered this problem? I would also try replacing your spark plugs, you might have fouled them out. Other then that, it sounds like ignition or timing problems. if you have a bad 02 sensor you should throw a code 41.

 

Thats the problem, it dont throw any codes......
I advanced my timing tonight,better throttle respons, exhaust still makes a poping(gerguling) sound when deselerating
Has not cut out yet, but have not driving it around long ,to see if it does still..
Cam-gears are set at 0...It did it before they were installed also

 

Check you cat. They can become clogged from time to time and would decrease performance.. Also use some injector cleaner if you have never done so already..