What does this mean po1 171 and po174 bank system to lean 2 system lean cyylinder 5 misfire

SOURCE: 2000 ford winstar sel update to problem

i had asimiliar misfire on my 2000 windstar.the first thing to check is a broken valve spring by taking off the valve cover the other is a o2 sensor bank 2 i believe is the downstream.if not the valve spring then either the coil pack or thecontrol module. either way it is fairly inexspensive

Dave C

• 1050 Answers
• Posted on Mar 26, 2009

SOURCE: vehicle failed emissions testing

You need to replace the intake upper plenum gaskets. There is two pieces, a top cover with one big silicone o-ring gasket and a lower half with six smaller silicone o-rings for the individual intake ports. You can buy these as a set, just for this job. Start this job by removing the wiper blades, then release all the screws, (including the ones that support the wiper motor), that hold that big black plastic valence at the back of the engine compartment. Pull that out of the way, you will have to pull the windshield washer hose through it, just disconnect it on the engine side, now you have access to the plenum. It's a pretty easy job now to remove and replace both halves, just a bunch of 8mm screws hold it all together. Take notes or digital pics along the way so you can pop it all back together. My only caution would be; when you have it apart, do not drop anything in the intake port! I always stuff kleenex in these while I'm working in case something slips out of my hands. Also, don't over tighten, it's all plastic. If you don't want to do it yourself, a shop should charge about an hour and a half, plus the codes must be reset and the van driven until all the monitors are ready.

SOURCE: Generic code PO171 system 2 lean bank 1 generic

This can be caused by a faulty mass air flow sensor

SOURCE: Codes P0171 & PO174 bank

http://leckemby.net/windstar/windstar01.html

SOURCE: check engine light is on

Look for vacuum leaks,that are causing the O2 Sensors to go lean, and set codes on both banks