Got misfire on ALL driver side bank cylinders (1-3-5-7) (3 Viewers)

[LOTFB]

I also have a misfire 1-3-5-7 error now. I changes all coils and spark plugs but still have the error (the engine has more power though). Compressions test showed some leakage but not terrible.
Any idea what this could be? Head gasket leakage? Worse?

 

[ClassyJalopy]

I also have a misfire 1-3-5-7 error now. I changes all coils and spark plugs but still have the error (the engine has more power though). Compressions test showed some leakage but not terrible.
Any idea what this could be? Head gasket leakage? Worse?

[EDIT] - looking at prev. responses it looks like @AFei 's problem was a clogged catalytic converter - it is worth looking into that first.

A misfire can be caused by a few things:

• What are the compression results for the driver side bank? Do they match the other side?
• Can you check the wiring harness (coil and fuel injector wires)
• When engine is cold can you spray some brake cleaner around the intake on the driver side and see if the engine RPM change? Definitely don't try it with warm or hot engine, have a fire extinguisher ready. I am not responsible for anything if you start a fire
• If all of those things check out then I think your next place to look would be fuel delivery - Since all cylinders are misfiring, I would suspect fuel pressure regulator on the driver side rail rather than an individual fuel injector