Limp Mode?

[Brysen]

So I've fixed up my mustang (2005 4.0 V6) and its running. but the car speedometer is messed up, (will say I'm going 80 when I'm going like 40), The car wont go past 2400 RPM, and seems to not want to shift at all, almost like its stuck in 3rd gear. It makes a pretty big jolt when shifting into reverse, and has a top speed of maybe 50 mph. The only code im getting though is p0174 (System too lean cylinder bank 2). another extremely odd thing that im going to check out tomorrow is that when i press the overdrive button, the anti theft light turns on and the car loses all power to the engine??? any help would be greatly appreciated

 

[Noobz347]

I would start by looking at the fuel system and injectors.

How long did this car sit? Was the fuel system ever cleaned out? Were the injectors ever pulled, cleaned, and flow tested?

 

[horse sence]

When mine did this same thing it was the wiring to the oxygen sensor ,burned one on the exhaust ,cut out the old ,soldered in the new and it cleared out