2002 Altima 2.5 Stalls after warm, no SES light.

[xzacto]

5-speed
So, Here are things that I have done to the car.

Got rid of the Pre-Cat so I don't blow up my engine.
• Put in Header SRS header
-Cheated the Upstream and downstream O2 sensors to bypass throwing code
• Installed Injen Cold Air Intake (CAI) - because... why not.
• Fixed Vapor Canister Purge Solenoid for an evap issue - the thing was RUSTED BAD!
• New Bosch Platinum spark plugs
• Previous owner replaced the throttle body and I cleaned the Mass Airflow Sensor (MAF)
• New ish Alternator also from the previous owner.
• replaced the Crankshaft Position Sensor (not sure of which brand) after it threw a code.

after I did these things I was getting 600 miles to a tank, about 190 HP and 36 mpg.
Right now I have about 170,000 miles on it, just changed the oil to 5w30 full synthetic mobil 1
We had a rainy day and I washed the car once as well, I had trouble after this.

When I started the car it stalled, but i can keep it from stalling and it runs. But the next day I drove it and after it got warm it felt like it was misfiring when engine braking down a hill. I got to a stop sign and the thing stalled like nobody's business. Getting it home was a chore, but on the thruway it was ok.

feels like there is 1/2 the power it used to have now too. No codes being thrown.