[dubyam]

Alright, guys, I've got a small problem with my 2011 CC Pro4X. I did an oil change and swapped the air filter a week ago, and since then, it's idling a little high and acting funny on downshifts. I've searched the forum and didn't find much to match my symptoms, so here's what's going on:

When I crank the engine, if it's cold, idle is high, like 1200-1300rpm. After it heats up, things normalize, so maybe that's not a real issue, but I don't recall it being so high in the past. What really bothers me is when I'm braking, as the truck now wants to rev itself 300-400rpm when I'm off the accelerator and foot on the brake. I've watched values in my Torque app, and what I see are two things which concern me. First, my short term fuel trims are all over the place (-8 or so up to 9 or 10) when I'm idling or just running along holding a low speed, like 35 or 45mph. Stick my foot in it, and it goes back to normal (-1.8 up to 2.4) and holds steady. Second, my throttle position sensor position jumps around, even when I'm not touching the accelerator pedal, from 2.5% up to 5.5-6% and back, with a corresponding increase in engine rpm. This is usually while coasting but does happen while sitting at idle.

Now, I think this could be one of three things. I could have a throttle position sensor out of spec, or I could have a vacuum leak (maybe from jostling the intake tube while wrestling the air filter cover back on the OEM box???), or I could have an idle air control valve going bad on me. What do y'all think?

I'm going to try to set up the TPS to relearn tomorrow morning, and see if that solves it. If it doesn't, I'll be headed over to the dealership (still just barely under the 5yr/60k powertrain warranty) but I'd rather avoid the dealership if I can, as it's inconvenient and they're not the sharpest tools in the shed.

Anxious to hear what y'all think might be wrong with my T.

 

[TheHops]

FFV or nah? Was it a drop in filter, or did you replace with a CAI? Can you view your AFR in that app, has it increased much?

On a side note, how do you like that Torque app? I just ordered a bluetooth OBD2 thingy yesterday and I'm gonna check out the app once it comes in. Any parameters Torque is missing you wish it had? I mainly want it for temps, AFR and MAF.

 

[CVTitan05]

Ive heard of the OBD2 bluetooth units show certain parameters bouncing around a lot like that, when they really are not. I wouldn't put a whole lot of faith in them, and would get a real scanner to watch those parameters. Maybe someone near you has a laptop and uprev they can help you out with? I would start there and verify that those readings are in fact true.

 

[dubyam]

I'm FlexFuel. Stock air filter replacement, too.

I like the Torque app, but wish it has trans temp, oil temp, oil pressure, and fuel pressure. Beyond that, it's great.

I'd be concerned about the OBDII Bluetooth adapter, but I've been using it for a year with zero complaints and the values have been steady until after the last oil and air filter change. The idle issue is showing up on the factory tach and I can hear and feel it, so the values in Torque jumping around (where they previously did not) seems to correlate, and I know the problem is for real, not just sensor viewed.

 

[TheHops]

I'm FlexFuel. Stock air filter replacement, too.

I like the Torque app, but wish it has trans temp, oil temp, oil pressure, and fuel pressure. Beyond that, it's great.

I'd be concerned about the OBDII Bluetooth adapter, but I've been using it for nearly two years with zero complaints and the values have been steady until after the last oil and air filter change. The idle issue is showing up on the factory tach and I can hear and feel it, so the values in Torque jumping around (where they previously did not) seems to correlate, and I know the problem is for real, not just sensor viewed.

No trans temp!? Damn...I was hoping for that. I wonder if any of the other apps support it.

That's interesting though. Personally I'm not sure what it could be. The maintenance performed seems very straightforward. A drop in filter should have minimal impact, and even so, a FFV should be able to adapt easily enough.

Are you sure the MAF cable on the intake tube wasn't jostled? Make sure it's connected properly. Could try cleaning the MAF as well if neither of those fixes it.

I would say start with checking the MAF cable, then the TPS as you said and work from there. I'll be curious to see if that's the fix.

 

[CVTitan05]

I would also suggest checking/cleaning the MAF, and then maybe to a throttle positioning sensor reset?

I dont think any other app will be able to read trans temp, ive only see the BDGT monitor it i believe. I dont even think Uprev has that parameter available. Though ive never checked...

 

[MikeClark]

Clean the maf and throttle body, disconnect the battery overnight and disconnect the obdII for a few days.When you reconnect the battery without the obdII, if the truck sounds like it's running better do a couple of wide open throttle runs to wake up the computer lol.