What to do? (Code 171, system to lean)

[gfisch]

My check engine light came on the other day, and i determined that the error code was 171. This is "System to lean (Bank One)"
After resetting the light about an hour ago, it hasnt come back on yet.
What would cause this, and is there anything I should do about it if the light doesnt come back on.
If it does come back on, what should be adjusted/replaced/checked?

Thanks,
Greg
'98 XLT

 

[Jason_25]

Do you have the SOHC? Have you had your intake manifold gaskets retightened?

 

[gfisch]

Yes, it is the SOHC.
Dont know about the intake manifold. I just bought it recently, but I havent since I got it.
You mean just tightening the bolts holding the manifold on, or replacing the gaskets?

 

[Jason_25]

Not entirely sure. But there is a TSB on it. Try a search on it and see what you can come up with.

 

[gfisch]

Maybe this is a stupid question since Im pretty new to this board, but whats a TSB?

 

[Jason_25]

Technical Service Bulletin

It's something Ford issues when they realize they screwed up on something.

 

[Robert]

When the light comes back on again within the next couple of weeks, go to Ford and have them perform Owner Notification Program 00M12 for no charge. They can check your VIN to see if it has already been performed or not. It involves replacing the lower intake manifold o-rings. Per Ford's TSB the o-rings could have gotten folded over during assembly or some other engine repair. My '97 SOHC had the problem show up at about 50K miles. It almost always shows up when the weather gets cold out which exagerates the air leak. I had the same code P0171 along with a P0174. Do a search here for 00M12 and you will find out a wealth of onformation regarding it.