Excessive fuel consumption
Mileage has dropped noticeably — under 12 mpg city or under 17 mpg highway.
M117.967 should return ~14/19 mpg with healthy systems. A rich condition is usually fueling, not ignition; ignition issues show as misfire first.
What the diagnosis checks
- Black smoke from the tailpipe at idle or under load?
- Coolant temperature gauge reading normal (~85 °C)?
Possible causes it points to
- O2 sensor or EHA stuck rich
- Coolant temperature sensor reading cold
- Verify with a tank-to-tank measurement
Parts for this job
KE-Jetronic fuel system sparesBackground reading
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