1997 Honda Civic

Engine Performance problem
1997 Honda Civic 4 cyl Front Wheel Drive Manual 250k miles

Autozone diagnostic test came back as " engine lean fuel trim". He said no parts needed only adjustment. Can you tell me where and what to adjust or do I need to take it in for specialized fuel metering? Runs rough at idle and losing gas mileage. Was 29mpg, now 23mpg. Thanks.E
April 4, 2008.

Might be nice to know what the code number was since there are two very closely related. Anyway, here is a list of things to look at.

- Air induction system (filter and breather system)
- PCV hose connection
- PCV hose
- Injector blockage
- Mass air flow meter
- Engine coolant temp. Sensor
- Fuel pressure
- Gas leak on exhaust system
- Open or short in A/F sensor (bank 1 sensor 1) circuit
- A/F sensor (bank 1 sensor 1)

Bruce Hunt
Apr 4, 2008.