P0171...

[diezelman]

Hello all,
SES light popped on this morning on my way to class, so I took it to Auto Zone for a check. Ernie finds P0171 "system to lean, bank 1".
From a little research I find, it could be from
- leaking injector
- bad O2 sensor (bank 1)
- fuel filter
- pump (possibly?)
- injectors need cleaning

Is there anything I am missing? Any suggestions as to were to start first?
I dont smell any fuel. I just replaced the filter 2 months back. Never touched the O2 sensors. Is cleaning the injectors something I can do myself in the garage?
BTW its a 97' SE 106,500 miles, with a bobble head chiwawa on the dash...

Any feedback is greatly appreciated gentleman

JP

[hoopsGTP]

Originally Posted by diezelman

Hello all,
SES light popped on this morning on my way to class, so I took it to Auto Zone for a check. Ernie finds P0171 "system to lean, bank 1".
From a little research I find, it could be from
- leaking injector
- bad O2 sensor (bank 1)
- fuel filter
- pump (possibly?)
- injectors need cleaning

Is there anything I am missing? Any suggestions as to were to start first?
I dont smell any fuel. I just replaced the filter 2 months back. Never touched the O2 sensors. Is cleaning the injectors something I can do myself in the garage?
BTW its a 97' SE 106,500 miles, with a bobble head chiwawa on the dash...

Any feedback is greatly appreciated gentleman

JP

You di dnot mention Engine Size, but that really does not matter. Was the Filter dirty inside when the fuel spilled out? I would check for intake gasket leaks, with the usual carb cleaner method. Spay where the intake meets the head and any vacuum line fittings. Fuel filter is basically a replace it. Fuel pump you will need a gauge to test the pressure, but it may be a flow problem which can be caused by a partially plugged fuel filter. Injectors cleaning... unless you know of some dirty fuel or if you have not replaced the filter in say 100K then cleaning is usually a last resort for me. Leaking injector checking is simple, while you have the pressure gauge on it to test for fuel pressure, just watch the needle. If it drops, pull the rail(Leave clips on the rail) turn upside down dry the tips off and pressurize the system by turning the key to the on position, not start. and watch the tips for any wetness appearing, one more than the other. In my years as a tech it was usually the O2 Sensor adn also the least time consuming test of all. Relpace it!!