I searched, just got a few ?'s and concerns...

Hey guys. Well I did a search before posting up a thread. My 98 windstar 3.8 is throwing a host of codes.

455-EVAP LEAK
302- CYL 2 MISFIRE
171-LEAN BANK 1
174-LEAN BANK 2

I want to fix the evap leak first. If the gas cap is good, then where should I go from there? Where is the evap canister located? Near the gastank?

Also, are these codes related?? If I fix the evap leak, will that fix the lean conditions in bank 1&2? What could be causing the misfire in cyl #2? Should I do a tune up? Gas Mileage is not so great on my van, it has 130k.

Please help, thanks

I'd check your MAF sensor - just downstream of the air cleaner. Cleaning it cleared the 171/174 codes I had in my escort. I used CRC electronic parts cleaner. I've read of success just using brake parts cleaner. Be careful not to break the thin filament wires.

Your '98 should have a very similar MAF to my '96 3.8L.

I have pictures on how to clean the MAF in my pictures at
http://community.webshots.com/album/201931518cScpNK

The evap. canistor....as I recall is located near the fuel filter.....which is under the car....just in front of the driver side rear wheel. The filter is on the inside side of the frame member.
The evap. canister is inside the same frame member.....near the fuel filter.

There is a vaccum solonoid mounted in the engine compartment.... on the firewall......kind of behind the upper intake manifold......toward the driver side.
This solonoid has 2 vaccum lines and one electrical connector.
The PCM sends a signal to the solonoid....telling it to open....and apply vaccum to the line that goes to the evap. canister.
I would check to see if there is a vaccum line off or loose...or damaged.

The vaccum source is tapped off of the PCV line.....as are a number of items....including the EGR vaccum solonoid that is mounted on the back of the upper intake manifold.....on the driver side.
So any leak in this series of lines could be a cause of concern.

I am mentioning a leak.....as this would also cause extra air entering the engine.....that is NOT measured by the MAF......so the computer does not know about it..... Which is the MOST common cause of the Lean codes for banks 1 & 2 (that is....any vaccum leak will cause this)

Auto part stores often try to sell you new oxygen sensors for the lean codes.....but it is VERY unlikely that your problem is being caused by oxygen sensors.......

I would try tracing the vaccum lines....starting at the upper manifold.....top....driver side (I had a leak develop through a crack in the elbow on top of the upper manifold)..... Follow that line back behind the upper manifold.....very hard to see back there.....but make sure that the line.....and all those plastic "T" connectors are intact....and that the line is firmly connected to the PCV valve.....and that the PCV valve is firmly seated into the gromet on the valve cover. (my PCV valve is in the Back valve cover).....I think that it was moved to the front valve cover in '99.

If you find a broken "T" connector.......I would buy a MOTORCRAFT PCV valve......I bought mine from www.rockauto.com
This PCV valve came with a bunch of plastic connectors.

Yeah nomie always tackle the first DTC most times it will eliminate some or all of the other DTCs

wow, this is so amazing! Thanks very much guys!! I never knew so much info existed for the freaking windstar minivan!! You guys are great help. I will try what was mentioned. Keep ya updated..

Nomie

Good News! I found the leak! It was the pcv pipe that attaches to the rear valve cover. Now Im going to reset the pcm by disconnecting the battery and hopefully I will loose some of the codes! Thanks and ill keep you updated. :)

Awesome and kudos to you!