so the rover has developed an intermittent miss...


I'll explain.


I am getting codes...
0174,0175,1174,1175


MAF is new Bosch.
New spark plugs.
New air filter


Compression test yields psi's from 100-120.
Head gaskets were done two years ago.
no burning oil.
no loss of coolant.
no mixing of either fluid.


car is running rough.
also, there is white deposits on the old plugs, running lean?


its not a steady miss, its while you're sitting, idling, you can feel a roughness in the motor.


the coil pack is the original one. wires are also two years old.


fuel injector o rings were replaced with the head gasket kit I believe.


few weeks ago, the rover would barely start. changed out the crank sensor, back of the block, and that fixed that, but the running rough still continued.


what should I do?


I am leaning towards ripping off the intake again and replacing all the gaskets. I am tempted to buy a smoke machine, I dont smoke lol.

 

To me I would guess vacuum or air leak. With the fuel trim off on both banks. You might get lucky and find a bad vacuum line or maybe loose intake manifold bolts.

 

what about O2 sensors?


I do have a snap on solus, anything that would tell me besides codes?


what about the ECU?

 

The o2 sensors might be fine. If you are getting un-metered air in it can cause the truck to run lean. So the sensors might be reading accurately.