Q: Unable to go past 70-80 Km when going up a hill. Code P0174 with flashing engine light

我最近获得了P0174代码，并且发动机灯在某些时候也闪烁（Misfire？）。我有一个福特金牛座1998。

The car runs fine except when I go up a hill it lacks power and cannot go past 70-80Km and if I give it more gas it does not increase in speed but instead goes into high RPM (around 4000). Maybe downshifts? Car runs fine on flat ground. I also have higher fuel burn then usual but haven't noticed any fuel leak. I do smell a bit of gas from the engine when it's running, but it's an old car so maybe it's normal?

So far I have cleaned the MAF, changed the gas filter, changed the spark plugs, put fuel injector cleaner, replaced the air filter and replaced a couple vacuum hoses that were getting old. The car now idles better then it used to but the engine light and lack of power going up a hill hasn't gone away.

我的汽车有250000英里。
My car has an automatic transmission.