I can only hope so. Trying to start an engine with an obvious and large fuel leak like the one you’ve described is really tempting fate. This leak needs to be fixed before attempting to start or drive the vehicle as it’s a major fire hazard.

Even turning on the ignition will have the pump spraying fuel everywhere from the leak, so I’d disconnect the battery until the hose is repaired and the leak stopped. There’s a chance the computer has detected the lack of fuel pressure, but whether that’s what is preventing the engine turning over is another thing. You may have multiple problems.

You’re right that error code P0171 on this car equals an engine that is running too lean. That is, There’s either not enough fuel or too much air in the cylinders. On this engine, many owners have found that the PCV valve can fail, but also that the rocker cover itself can contribute to vacuum leaks. If you can hear air hissing anywhere, then a vacuum leak somewhere around the engine is a pretty good bet.

But let’s not forget that a lean mixture can be caused by not enough fuel, as well as too much air. In which case a check of the fuel filter, fuel pump delivery volume and pressure are warranted. You can also get a lean error code from a faulty or dirty MAF sensor in the engine’s intake system.

The filling point for this transmission is on top of the gearbox, under the ECU (drive-line computer). So, to access it, you’ll need to move the computer (which attaches to the battery tray) out of the way. Take lots of photos before removing bits and pieces so you’ll know how it all goes back together.

However, it’s doubtful that a lack of gearbox oil is your problem here. If the oil was low, the transmission would probably be making some seriously bad noises or would be completely seized up, not just refusing to shift out of reverse. The refusal to abandon reverse probably has more to do with a mechanical selector problem. But don’t rule out a worn or maladjusted clutch, either.