Hey guys i recently got a 97 firebird with the 3800 series 2 motor, I've noticed the car tends to shudder when accelerating sometimes and the exhaust smells very rich, after talking to a few people i was advised to check the evap system and I found the evap switch thats supposed to be mounted close to the firewall is missing the plug is there and the line that seems like it should go into the switch then the solenoid goes straight to the solenoid. is this likely the problem? also i noticed today the coolant reservoir has a brown sludge in it is this the dex cool problem i've heard about it doesnt look like oil, closer to the color of mud thanks for your time everyone