car runs bad, fan on during cold starts

[bvass]

So my car has been running like crap lately. I have searched the forums for a week to no avail. Here are the symptoms:

the passenger side fan is always on (cold starts included)
When the car is cold and idles if I hit the gas it tries to die as if it is choking (it doesn't happen when it warms up)
I get a random misfire when I cruise
I have to press the gas a little harder to maintain speed while cruising and my vacuum guage reads between -4 and -0 while normally it is between -15 and -10
When i get in boost the car backfires bad around the 4.5k rpms mark.

Here is what i have tried so far:

New Spark Plugs
New Spark Plug Wires
Different ignition coils
Compression is 175 across the board
No boost/vacuum leaks
Timing is dead on
New Temp switch (the one with the 2 prongs)

What else can I try?

 

[stefanOst]

Any CEL showing up? I had some cold start issues over the summer and it turned out to be coolant temperature sensor, and a few other threads I have seen since then have had similar takes.

 

[bvass]

No CEL. I have read those threads as well and I replaced that switch/sensor you are referring to. It didn't help.

 

[lauj2gdsm]

Kind of an old thread but did you ever fix the problem? I have the same exact problem and i have gave up hope parked the dsm.

 

[lauj2gdsm]

anyone?

 

[waterman412]

one of my buddies had similar problem and come to find out his catalytic converter was kinda plugged. after fixing that the car started and ran fine.