PO171 states 'engine too lean, bank 1'. (cyl's 1-4 on passenger side, I assume)

Incidently, this is an E150. I assume it is no different that F series.

The engine runs like a top. There have however been some incidents that proceeded the two occurances of the code.

1) two weeks ago I did plugs and plug wires. This was somewhat intrusive as you had to reach clear to the back, over and under who knows what. Unlike the F series you can get to the rear cylinder thru the dog house.

2) one week ago I replaced the alternator. Not an intrusive job as everything is right up front.

3) The morning of the first 'check engine light' occurance, several days after the alternator and a week plus after the plugs and wires, I started the motor a few minutes b4 I had to take off. It started well, ran a few minutes, then just up a quit. No muss, no fuss. No snorting or backtalking. Just like you turned the key off.

I finished what I was doing, got in and restarted it (no problem but it had never done that before) and headed down the road. Later in the afternoon, after miles of freeway driving, I started it after a stop and the 'light' came on. As far as I could tell there were no running issues.

I checked the code and erased it, now three days later I went to the store, came out, started the engine while I fastened my seat belt. There was one quick stumble of the engine and the check engine light came on again. Otherwise the motor ran like a top all the way home.

I am assuming that the second occurance is the same code. I have not read it yet.

Any ideas where to look? If it was a vacumm leak, it would be continuous. If it was an oxygen sensor, the computer would tell you. If it was an injector, the computer wouldn't just say 'bank 1'

Are there code readers that give more detailed info?

How many occurances, over what period of time, cause a check engine light to come on?

Is there any possiblity that a long overdue fuel filter change could cause some fuel starvation? It seems that both times the issue occurred at idle.

 

You may have left a hose off of the air inlet tube or the pcv came out of the grommet.

 

Yeah antony, I'll get in there and see what I can see today. Thanks

 

You got it right antony. The rigid PCV line is just hanging in mid air down on the passenger side of the motor. I must have knocked it loose when I lifted the alternator out. Thanks again.

It's so hard to see into a van engine bay and know what you are looking at.