rough idle when fan turns on

[06vtwrx]

ive got an 06 WRX Cobb AP v2 Stage 2 map runningt 93 octane, catless invidia DP with invidia N1 exhaust. my car ran great for 2 weeks after i went stage 2 with my WRX. then one day my car over heated for barley a minute i pulled over and let the car cool down started it back up and it didn't over heat again then 2 days later i was having the rough idling problem. i brought the car to a mechanic and they did a compression test on the motor and it tested perfect. the head gaskets are fine. i believe it may be a vacuum leak but i cant find a leak anywhere. i tried unmarried my AP and reinstalling it and that didn't work. the car only idles hard when the fan turns on. my car when fully warmed up runs anywhere from 175 - 190 degrees F. fan turns on at 195 - 200 F. it also seems like iv lost horsepower from this. when the car idles rough my live data from my AP states my lower point is 300RPM and it jolts the 1500 to 1800RPM. the car sometimes completely stalls in neutral but hasn't ever stalled out hard it always stalls softly. i called and left a message today at ECS and im waiting to hear back from them. this has been going on for a month and a half now and my machanic said that it was the fact that my car was catless. please help me.

[shtbxr22]

catless will not cause this. time for new plugs? due at 60k. worstcase scenario, you have a cracked cylinder liner, or cracked somewhere in the head. what was "perfect comression" at anyway? spec is 142-171 psi. any leakdown test?

[06vtwrx]

I unpluged my MAF last night and waited forthe fan to come on when the fan finaly came on it didn't idle rough at all. Time for new MAF?

[BG @ BrenTuning]

Clean maf (up internally not just the iat teardrop), seafoam car (diy thread in my forum) and then change plugs. Then go for a custom tune.

[06vtwrx]

So i bought a can of CRC MAF cleaner at my work today. i also have a brand new MAF sensor on the way. i got a new set of plugs today. im gonna put them in on my day off. i cant find Brens link to seafoaming can someone send me a link. any other ideas anyone? i hooked my AP up today when i hit boost my air/fuel ratio drops to 12.0 to 13.8? Bren how much for a tune?

[06vtwrx]

Bump

[javasti2004]

could a altinator be the cause do you have aftermarket radio with subs andall that? maybe the draw is killing the spark energy? check altinator output should be 14. something volts. its and idea anyways that takes 2 seconds to check. the fan kisking on could be drawing just enough to mess with it

[javasti2004]

have your battery tested too i have seen bad batteries do stranger things