Recently changed the lower intake gasket on my 96 Series 2 3800. [non supercharged] While I was at it I installed a new upper intake. I was experiencing some unexplained coolant losses, which now seemed to be fixed.
However, after completing all of this work, I now have a slight hesitation, a slightly rough idle, and some shuddering in overdrive, none of which were present before the work was done.
[At least not that I recall]
I took it to my local mechanic, he did code test on it, [the engine light was flashing if you pushed on the accelerator too much] and the 02 sensor showed it was very slow in responding. He thinks the previous coolant loss [lower intake gasket was pathetic] has ruined the sensor...?
He also found 2 less than perfect ignition wires. He suggested replacing all the wires and plugs, a new 02 sensor, and having the injectors flushed.
I replaced all the wires and plugs, and it seems slightly better, but still far from perfect. Three of the plugs were "white" instead of grey. Would cleaning the injectors and changing the 02 sensor help any further?
Iím wondering about a slight vacuum leak
, but have not been able to find one in any of the lines, or by spraying break cleaner all around the lower intake and the injectors.
Any ideas guys?