PO171 System To Lean Bank 1, What Does This Mean?

Question

I just had my 02 VW Passat 1.8 Litter worked on because I had a POO31 Heater Control Circuit Low Bank 1, sensor 1 replaced, now I have this error message, PO171, System To Lean Bank 1.

What is going please?  I am ready to throw this car away, I inherited it from my mom after she passed away, and I've had nothing but issues.

Answer 1

After so many use and service components wear out, When there is a lean code condition, what happens  most of the time is vacuum leaks, What you want to look for is the  common wear item that should be inspected because they do cause lean code condition.

​ The crankcase valve and the PCV with its hoses if it deteriates it can cause false air leak which results in lean code condition

​ Broken dipstick tube this can cause false air leak which results in lean codes