While cruising at 2k rpm, I can feel a drop in power that comes and goes. I dunno how to explain it other than it feels like I'm on the gass/off the gas. It's not dramatic but I can feel it. Car info:
IX MR
Running 8950015 rom
Tephra mod 5.1 though the only things I enabled were valet mode and O2 simulator. .
I left tephras maps alone.. Assumed they are stock; I have done no tuning.
3" TBE, no cat.
Burschur air intake/MAF adapter/air filter.
Can the intake/exhaust be throwing things off THAT much? And if so, wouldn't it help with the stock over-fueling any way?
I logged a 1 or 2 knocksum but for only a few cells of the data log. Nothing over 2.

Any suggestions?

 

ttt

 

bump

 

here is my data log. i see some weird stuff going on with the airflow portion of the low right when i'm going lean.

it's a perfect "150" during all the cells where i'm going 16:1 - 18:1 AF. then goes back to reading normally when my AF drops back down.

can anyone tell why i run so poorly below 2k? i also have a miss during idle.

notes: i think i bought the wrong spark plug. maybe the guy that bolted in my MAF touched it or it's otherwise dirty?

http://home.comcast.net/~kaj750/datalogpoor2k.csv

 

found the problem. auto parts store sold me VIII plugs. we all know how much shorter those are then IX.

bought Densos. all fixed.