I don't know if this topic has been covered before but, recently car's cel came on with codes p0171 and p0174. All 4 of my o2 sensors were changed within the last month. Also my car run rough on startup for about 10-30 seconds depending on how cold it is but then idles back up at about 1k rpm. The tp is reading at 14% at idle so the app sensor was also changed but still read 14%. The car loses all power if I give it more than 60% throttle and will almost never exceed 60mph. Any advice or help would be appreciated.

 

what brand o2 sensors?

 

Denso

 

Lean codes and no power? Check fuel pressure.

 

the shop checked and said I had normal fuel pressure

 

If you're going through the shop let them come up with solution and fix your car.

If you want to fix the car yourself, do all the checks yourself.

I would check fuel pressure while engine is under load. Idling or simply commanding fuel pump ON with scan tool is often not enough.

 

Dirty injectors and vacuum leaks will give you lean codes.