"Check Engine" light came one....

[DB_1]

"Check Engine" light came on....

So it came on about 2 weeks ago and it finally annoyed me enough to find out what the deal is. I went to Auto Zone to borrow one of their code readers
to check it out and got 2 codes off of it:

PO171....System adaptive fuel too lean (Bank 1)
PO174....System adaptive fuel too lean (Bank 2)

I looked in my Haynes book for further details but it didn't tell me anything more than the code reader showed me.

So what's Bank 1&2 mean and what do I start checking out?

 

[99explorer5.0]

Not sure if this will help but i did a search on google and found this Its for a windstar but could be the same???

http://www.talkaboutautos.com/group/rec.autos.tech/messages/534533.html

 

[DB_1]

Thanks 99Ex

That gives me some good info to start checking out, namely my oxygen sensors.

I got a great link off your Google link...something everyone here could use:

www.troublecodes.net

 

[cfkane]

Mileage on the vehicle can be an issue for what you have described. If it is higher then aged O2 sensors or a MAF with deposits on it (in addition to other things) can both cause the readings you have. Look for any lean run symptoms such as plug wear or color. You may also be experiencing /lean burn misfire in the form of surging at constant speeds. This tends to be worse at higher temperatures with some drivers reporting a mild ping. Absent exhaust gas CO/CO2/HC information the simplest thing to do is clean the MAF followed by replacement of the O2 sensors if they have significant miles on them.

 

[Glacier991]

Welcome to the Board CFKane. I can already see you will be a good addition to the knowledge base here.

 

[cfkane]

Thanks Glacier, your kind words are appreciated.

 

[tdavis]

Have you ever replaced your O2 sensors? If not, I'd do that first.

 

[DB_1]

02 sensors have been changed once during the life of the vehicle (97 Ranger w/ just over 100K) and plugs have been changed twice. I bought a couple a O2 sensors last night and upon installing them I forgot there was one more to buy. So a total of 3 of those damn things to buy and they aren't cheap as you well know. I still have the 3rd to install and i'll see what that does. I'm gonna pull some of the plugs and see what those look like too. Keep ya updated,
Dave

 

[DB_1]

Ok, that 3rd sensor has never been changed...i know this because I would've remembered what a PITA it was to change it. I could barely get to the clip on the harness to undo it and it was equally hard to get a wrench to the bung on the downpipe. So all the sensors are changed and I warmed up the truck to operating temperature and still the check engine light is on. Do you have to reset the code and then see if it comes back on to see if the problem exists or does it go off if automaticly? (if there's no existing problem anymore)
I still need to check the plugs, vac. lines and MAF to see if everything is ok there.

 

[cfkane]

Disconnecting the battery for 30+ seconds to reset the EEC is the fastest way to get the adaptive map back to a neutral trim. You may want to take a quick look at the MAF for deposits and clean it as needed. Depending upon the code and the OBD II implementation the light may require a scan tool to reset. Do the repairs and EEC reset then see what happens.

 

[DB_1]

Thanks cfkane, I'll try all that and see what happens. They are pretty cool here at my local Auto Zone as far the the tool loan goes. The guy told me I don't have to actually rent the scan tool for $180.00 deposit (they charge your credit card then credit you when you are done) he said I can just leave my drivers license and use the scan tool in the parking lot.

 

[DB_1]

I cleaned the MAF and checked the plugs and they looked fine. I also checked out the vacuum lines. I disconnected the battery while I did all this and after I was done I reconnected the battery and started up the truck...no more "check engine" light I let it get up to operating temperature just to make sure everything was ok....so far so good.

 

[thundertiger]

Hope you fixed it But!

Hi i had the same problem with my 98 sohc but what i did to fix it was to change the upper and lower inlet manifold gaskets and at the same time clean the iac valve with a good can of carb cleaner the gaskets definately need doing.

 

[DB_1]

With 104K on the odometer it wouldnt suprise me that the gaskets need replacing or anything else for that matter so i'll check that out too. The IAC was replaced earlier this year, the howling noise it was causing was driving me crazy.