I got this car a out 3 months ago now. Swapped engines with another 3.2 and here's how it goes. It starts and runs with the codes p0301, p0303, p0306, p0300. All coils firing, new plugs, compression tested all cylinders #1 190 #2 200 #3 200 #4 190 #5 200 #6 190. Fuel injectors all working. Fuel trim on 02 sensor bank 2 sensor 2 fluctuates between. 10- 42. New cold air intake all sealed, throttle body sealed mo leaks. Sprayed starter fluid under intake manifold and idle seemed to smooth out for a couple of seconds. I got silicone and revealed all gaskets not alot but so it was an unbroken bead on all gaskets. Exhaust on bank 1 side I need to put 2 more bolts to hold it together only has one in it. Okay so my question is sense the 02 sensor is reading the amounts just fine but it's reading high amount of oxygen and I'm pretty sure with the last 2 bolts it should take away the high reading and stop dumping Fuel in to the engine my mpg is at 11. Now with the started fluid causing idle to smooth out being sprayed under intake at #6 side where injector is that means a leak in the gasket there right or one of the gaskets there nothing with injector right. I've done a valve adjustment on this engine already so not the cause or misfires. Just need advice on what is most probable cause of miss right now ive torn down engine to heads

 

leak down test?

 

Moderator Note: Thread moved to model specific forum.

 

Warped intake?

 

I have not done this yet but I will do this tonight and post what the readings are in the morning. Thank you