P0172, P0175 Not a big problem yet but, where should I start?

I'm getting an intermittent simultaneous P0172 and P0175 popping up. I clear the codes and they don't come back immediately. Over the last couple of months, here's what I've observed to make the codes rear themselves. I have a one mile drive to work, rig doesn't get to operating temps. Most days all I drive is to and from work. I coach a few of my kids city soccer teams and I drive a bit more on those days. Neither will cause the codes. I've taken some longer road trips, 3+ hours one way, and while driving nothing is remarkable. At the end of a long stretch, when I get to where I'm going and I'm slowing down, parking, or waiting somewhere, idling, is when the codes pop up. With all that said, basically, the codes pop up together after a long drive and then slowed at idle. When I start my rig in the morning, I definitely get the unburned fuel smell that most people says comes with the codes. What the first, least expensive place to start looking for the problem? Thanks for any input or help you can provide.

 

This is impacting both banks if throwing both codes. It could be that the ECU isn't getting correct info about how much air is coming in, so it's dumping too much gas into all cylinders. Or it could be that there's something else happening that would resulting in excessive fuel.

Let me ask you this: When was the last time you cleaned your MAF using labeled MAF cleaner? Or have you yet, just to see if maybe there's microscopic buildup on the MAF internals?

Do you have a multimeter/DMM, that you can use to follow the FSM's recommended test to verify the MAF?

 

I was wondering if you may have an explanation as to the timing of the codes popping up. They don't come up if I'm just running quick trips. The only fault after a longer trip and not during the trip but at the end of it when I'm idling parked or at a stop light for a while. Why only then? That's part of what's puzzling me.

Over the past couple of months, I've given it a good spray down a couple of times. Honestly, I've been thinking about just picking up a new one. They're not a trivial cost though.

I've got a multimeter but, haven't tested the sensor. I'll try to look up the testing procedure.

 

Is it something like this?
https://www.youtube.com/watch?v=71E0U99omUw

 

Check CTS sensor along w MAF. Might be triggering too much fuel under false hot operation. Just a guess.
Shifty is prob right, diag via fsm. I dont hear about cts related rich conditions w fgt. Always a/f sensors " upstream O2's" MAF ETC...

 

Yes, the test process and specs it should fall within are in the FSM, which the owner should reference for their own engine.

Note the resistance measured will vary depending on outside temperature around the vehicle.

It's a very simple process, I don't think the video you posted is any easier to understand than what is in the FSM. And a copy of the FSM is avilable for free download in the new owner/megathread sticky.

 

Ordered a new Hitachi MAF sensor and all is well again with the world.