Focus Fanatics Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
I pulled the codes from my ZX3 2001 due to the check engine light. I pulled the detailed information showing that the BANK 1, how a low/to lean error. If I am correct, Bank one is pre air intake. My initial guess was the Ox sensor. Can anyone verify this diagnosis? Or shed some light as to some other places I should look. I have taken extensive time, looking at all my PVC and nothing seems to be off or split. I heard that this can be related to the fuel filter and beyond, yet I am hesitant because of the "bank1". Let me know if anyone can help out.
 

·
C2H5OH
Joined
·
11,867 Posts
Bank 1 is just the designation for the front Oxygen Sensor, the one before the catalytic converter. What the code indicants is that it has seen a prolonged lean burn condition or has seen a lean condition more than a few times.

You may be on the right track by checking for vacuum leaks, the PCV elbow is prone to deteriorating and the whole intake tract is prone to oil mist than may or may not be an issue (gummed up valves, gummed up Idle Air Control Motor).

You may want to try sucking some sea foam through a small vacuum line into the running engine. Some have had luck doing this, I personally have not (but I have bad luck the way it is).

It may have just been a fluke and a result of a bad tank of fuel. It does happen.

Or it could be a failing Oxygen Sensor. I believe most good shops are able to test the O2's response time and see if it's life is nearing the end. Generally when they fail the response time goes way up, or is just nonexistent.

There is also the known Fuel Pump Module problem. But fuel starvation around corners and under heavy load are generally associated with that problem.



The simple things you can do are check for vacuum leaks, which you did and are doing. Replace the fuel filter, lets say if it has not been done within the last 20,000 miles. Check the spark plugs and wires, misfires or poor combustion could be to blame.
Other than that I would say to get it checked out so you're not throwing money at it and wasting money by fixing good parts.
 

·
Registered
Joined
·
268 Posts
Bank 1 on a focus is your engine. It is a generic code as are all the P0xxx codes. A P0171 is lean bank 1 code and a P0174 code is a lean bank 2 code. That way they have the same list of codes for 4cylinder 6cylinder 8cylinder..... Rarely is a lean code due to the oxygen sensor. More often it is a vacuum leak or a mass air flow sensor problem. It can be anything out of a long list of things but vacuum leaks and maf problems are the most common.
 
1 - 3 of 3 Posts
Top