P0170 - BMW 520i 1999

Question

Goodevening ,
Three days ago i replaced the pre-catalysator and post-catalysator sensors on my own . The car starts fine but after 2-3 minutes the problem begins . Τhe idling is low and isn't properly feeded with fuel and as a result it trembles . Any advise please ? I am not sure if i have to change any other parts or if i have to check again the catalysator sensors .

Answer 1

P0170 Fuel trim lean malfucntion Bank 1

This is a condition where4 there is more air to fuel ratio. Check it intake boot and the oil cap, and the dipstick, If P0174 is also accompanied with this code the fuel pressure should be checked. but for now check for vacuum leaks and this includes the valve cover gaskets