An odd problem started in my 05 Limited Coupe a couple weeks ago. When I come to a stop the idle will fluctuate between 600-2000 RPMs a few times before it settles down. If I put it in neutral, take my foot off the gas, and let it coast on the highway it will do the same thing. In other words, it only does it if my foot is completely off the accelerator.

Anyone deal with this before?

Thanks

Curt

 

Oh, forgot to mention a couple new codes appeared when this problem started. P0171 (bank 1 lean) and P0174 (bank 2 lean). Thanks.

 

I would bet you have a loose/broken/split vacuum hose somewhere.

 

I did check for any obvious leaks before posting. I"ll take a closer look tomorrow.

Is there a test to determine if the MAF is bad?

 

Not really, but you can get a can of MAF cleaner spray and see if that helps.
Old trick is to use an UNLIT propane torch and pass it slowly around all vacuum lines, if the engine smooths out, you have located it.

 

Or spray Carb Cleaner around hoses. RPM changes, you found it. Propane... Hmmmmm...Not Me.

 

In days of old, that's how you would check for a freon leak. The flame would turn blue or green, when the two mixed. In days of old , we did things that are now considered, improper, illegal ,immoral, unthinkable and not politically correct.... It wears me out....lol

 

In the Old Days, I'm older than you. Considering some of the things we use to do its a wonder we are still here. "With age comes Wisdom" only works if we actually use the Wisdom.

 

How true....love that!

 

Yep and I for one will proudly continue to do so simply because it works and it makes the Millennials mad, LOL!!

 

And tires lasted until the tread was gone, trailers carried as much as you could pile on, and a good tune was done by ear.


Of course back then a 6 cylinder was a slug, automagic transmissions were two or three speed, without lockup you needed a trans cooler if you pulled a race car, and a set of Wide Ovals was $100.

 

Ahhhh! The good old days, adjust the carburetor with a screwdriver and by ear adjust the point dwell and timing by ear, filler up with Sunoco 260 and down the road you go happy as a lark.

 

Upon closer inspection I did find a crack in the 1/2" hose going to the right bank. I guess that's bank 2? Not sure why it would cause a fault in bank 1 but I'll replace it, reset the codes, and see how it does.

While I had everything off I was going to remove the MAF and clean it. The book procedure didn't work. I disconnected the harness and hose. I loosened the lock ring thingie (although it was already broken on 1 side so didn't do much. I then pressed on the tab at the bottom. The book says it should come right out but it didn't budge. There looks to be another lockring holding it to the manifold but the book said nothing about that one. So I'll just leave it alone for now. I don't want a simple hose replacement to turn into a 2-week headache.

 

On the MAF sensor, there are 2 security screws you remove an can slide the sensor out to clean then replace. Harbor freight has a small set of the torx bits for sale at about $6.

 

So the small part that the harness connects to (held in by the 2 tamper-resistant screws) is the part you remove and clean? I thought the entire housing had to be removed for cleaning.

 

You can clean it either way, in or out of the housing.

 

Just don't touch it...