Po171 Po174

OK, i did the tsb for the po171/174 codes about a week ago and everything was fine until today, my check engine light came back on. I plugged my code reader in and now I'm only getting the 171 and not the 174. Any ideas as to what my problem could be now? When i plug my code reader in I'm also getting a 0181, a 0497, and what appears to be a 07E5(I'm not sure on this as I thought all codes for obd2 were numeric only), It does not list any of these 3 codes in the list in my Haynes manual. has anyone ever run across this.

I haven't noticed the van running or idling badly yet. Before i did the tsb I was having problems occasionally with it idling rought and dying at idle, and also occasionally a minor miss when accelerating. Havent noticed any of that since the doing the tsb. Any help would be appreciated. Thanks.

the 0497 - Evaporative Emission System Low Purge Flow

the 0181 - Fuel Temperature Sensor A Circuit Range/Performance

the 07e5 - couldn't find anything on.

Hope this helps.

I did go back and look in the cheesy manual that came with my codereader and did find the 181 and 497 in there, they were not in my Haynes manual, though, which seems odd.

Now does anyone have any idea what those codes mean and what the problem might be?

Also, any idea why the 0171 has come back already, but not the 0174? thanks.

I have a '96, so things will be different on your newer windstar.
I thought I would mention one thing that may help you.
The evaporative system runs off of the vaccum in the intake manifold.
My '96 taps the vaccum source for the evaporative system off of the PCV line going between the intake manifold, and the PCV valve.....yours may tap off at a different location, but the principle is the same.

There is a vaccum solonoid.....which has an electrical connection, and 2 vaccum lines. One vaccum line is to the constant vaccum source (when the engine is running) and the other vaccum line goes to the charcoal canistor, which is back by the fuel filter (under the car).

The PCM sends a signal to the evaporative system vaccum solonoid, and enables the vaccum to go to the evaporative system....pulling the fumes into the engine.
The OBDII system monitors the flow through the evaporative system.

That all said...... There may be a connection between the lean code (P0171) and the evaporative system code......such as a leak in the vaccum line to that solonoid. Could even be disconnected.
This would cause both a low flow for the evaporative system, due to reduced vaccum, and extra air into the intake that the PCM does not know about.