What is the most common cause of p0171 code on 2004 saab 93

Question

The engine hiccups during acceleration and occasionally throws p0171 engine too lean code.
Yesterday after some 60-100mph highway acceleration I found the dipstick out about an inch and motor oil had sprayed out onto the engine. Help will be greatly appreciated.
Thanks

Answer 1

HI there

The most common cause for this code is a bad mass air flow sensor. Sometimes an intake manifold gasket leak will also cause this. If it's blowing the dipstick out though, you might have a valve or timing issue allowing to much compression back into the engine.