p0171 2001 van

[nogto]

A few months ago I added half a bottle of quality fuel injection cleaner to my 2001 Windstar. Next day the engine light came on!? So I took it to Autozone and they put the scanner tool on it. (It is storing one trouble code, p0171)

After searching the archives, I'm a bit overwhelmed by all the possibilities of this code, and of course my Haynes book is basically worthless.

Here are my questions:

Should I try replacing the pcv valve and grommet? It's fairly loose in the valve cover.
What is an IAC valve, where is it located, and how do you clean it?
Is there a chance that I harmed the o2 sensor(s) when I added the injector cleaner?
Where exactly are these isolator bolts located on the engine? And is the job do-able for average wannabe' mechanic?

FYI---This van has 92,000 miles

Thanks!

[DRW1000]

I will only answer what I know.

A PCV valve should be snug. It is a cheap replacement. I doubt this is the problem but I say do the simple things first.

The IAC (Idle Control Valve) is normally on the throttle body. It allows a controlled amount of air to enter the intake when the throttle is closed (idling). If it is stuck open then it could cause a lean condition but one would tend to believe that you would have both codes (P0171 and 174) although one O2 sensor may be more sensitive and the other is close to giving a lean code.

Was the Fuel injector cleaner the type you add to the fuel tank? If so I doubt you damaged the sensors. Just a coincidence. 02 sensors do not like silicone and most additives will mention if they are sensor safe.

The Isolator bolts are in the intake. You would have to remove the upper intake to see them.
There are a lot of wannbee mechanics doing this repair but it really does depend on your own abilities. It is not a difficult job but it does take some time and you need to have the proper information and tools (read torque wrench).

[nogto]

Thank you.