Had tranny fluid changed and now getting P0170 and P0174

After they changed the fluid, the car drove home fine. The next morning, after startup from cold, it would have an oscillating idle - faster than normal and then slower. I had my wife shut it down and I checked to see if there were any codes - none. She drove it without incident the rest of the day. Today she said it did the same thing so she revved it a little and she said it started behaving again. This evening, we were coming home and the CEL came on. I read the codes (P0170 and P0173 each of them displayed twice(?). The scanner software says that one set of P0170 and P0173 are stored and the other set are pending. There didn't seem to be any driveability issues before the CEL came on (I noticed it just as we drove into the garage.
It seems that it could be a vacuum leak. I took off the air filter housing but didn't see anything obviously disconnected or damaged. From my reading of the procedure to change the tranny fluid, there didn't seem to be any vacuum hoses that would be disconnected.
Does anybody have any ideas?
Thanks!
Last edited by ncmudbug; Jul 19, 2014 at 07:37 PM. Reason: I had the wrong code.

I'll try that tomorrow.

Z, do you suspect that it will "fix itself"?
Last edited by ncmudbug; Jul 19, 2014 at 08:09 PM.
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It is pretty straight forward to take it off and put it on, right?
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I'm going to have my go at cleaning the MAF today but this morning it had the same idle issue (oscillating between 800 and 1000) till it warmed up a little and then it was fine. So far no codes but if the condition isn't any better, I would expect them later if I don't do anything.

I cleaned the MAF and the throttle body (for those contemplating this, there is different cleaner for each. You should be able to get it any reasonably supply auto parts store). The throttle body was difficult to get good access to because on the V6 engine, it is in the back near the firewall. An inspection mirror is really handy here. It seems the MAF includes the tube it's in. That confused me because all the pictures I'd seen looked like it would come out.
I put it all back together and it drove really well but the final test was when Mrs. NCMudbug took it out this afternoon because it was dead cold. The only problem was a squeaking brake! No CELs, not hunting on cold idle - or any idle for that matter.
Thanks Glyn and Zayed for your help!







