问：错误代码P0171和P0374

我使用了OBD II / EOBD代码读取器，并找到了以下代码（4个错误代码）P0171系统太精简银行1，p0374正时参考参考hig n分辨率信号a no脉冲，P0171系统，系统太精简银行1，p0374正时n分辨率参考参考参考参考参考信号无脉冲，

相同的代码读取器给了我RPM（RPM）：705.50发动机运行时，但装备处于停放位置。

I don’t feel anything while driving the 2006 Ford Five hundred SEL (I don’t have much knowledge about vehicles), It accelerates well and goes easily to 40miles per hour when given the acceleration (I have not tried beyond 40 miles/hr in order to avoid any damage, as I bought it recently and want to repair it before use) the odometer reads about 200,000 miles, I showed to a local mechanic he said the gear is either in 2nd or 3rd (limp mode) after a short test drive, which made me little worried, what can be the possible reasons of this errors and what should I do to make it a smooth running vehicle?

我的车有200000英里。
我的汽车有自动变速箱。