Code 12 is normal you should have that code.The code 32 is for the egr valve is for most likely a sticking egr i would remove the egr valve and slowly push down the pintle till it bottom's out and then slowly take the screwdriver away from the pintle.See if the pintle closes all the way and doesn't stick.But from the surging and the code's it sound's like it's sticking.The code 33 is for map sensor high voltage i think the egr valve is causing that code so let's fix the egr code first.I posted instruction's on how to remove the egr valve the Picture of the engine is different then yours but the egr look's the same and is held in place by two bolt's like yours Let me know what you find.
1. Turn ignition Off.
2. Remove the air intake tube.
3. Disconnect the linear EGR valve wiring harness terminal.
4. Remove the linear EGR valve attachment bolts and valve assembly.
NOTE: The linear EGR valve should not be soaked in any solvent; otherwise damage to the electrical solenoid can result.
NOTE: Remove all loose deposits from the EGR inlet passage, otherwise they could clog the EGR valve.
5. Inspect the cylinder head, linear EGR valve and adapter passages for excessive carbon deposits. Deposits can be removed using a screwdriver or 305-330 mm (12-13 in.) length of odometer cable.
6. Clean the EGR valve mounting surfaces and inspect for scoring and cracks.
1. Install new EGR valve gasket.
NOTE: Make sure gasket is installed correctly or a vacuum leak will occur.
2. Install EGR valve.
3. Install EGR valve attachment bolts.
Linear EGR valve to cylinder head Torque to 25 N.m (19 ft-lbs)
4. Connect linear EGR valve wiring harness connector.
5. Inspect air inlet tube. Attach air inlet and tighten clamp.
6. Install fresh air hose.
7. Start engine and inspect for exhaust gas leaks and diagnostic codes.
Saturday, September 25th, 2010 AT 12:57 PM