2002 LW-200, automatic. suddenly started chugging at stops; the whole car rocks.
This showed up suddenly. The car runs fine at highway speed and
accelerating/decelerating. long-time saturn mechanic can't find the problem; diagnostic
just says 4 cylinders missing. he tried plugs, wires & coil but it didn't help. He was
thinking injectors, but said it should show this problem at hi-way speed also. He
suggested a possible ECM replacement ($500-600) *might* help, but wasn't confident,
otherwise disassemble the engine to look for problems (burned valves?).
I asked about the Catalytic converter being plugged (happened on an earlier car), but
he didn't seem to think that was it.
Anyone have suggestions?