My kid's car is a 2009 Scion xB, but it's the exact same engine (2AZFE) found in 2002-2011 Toyota Camrys.  

The battery died, so she installed a new one.  Now, it idles too slowly (about 500 rpm, normal idle rpm is about 750 I think for automatics).  It shudders, but doesn't die.

No check engine light/MIL.

Spark plugs and 2 coils are new as of 10K miles ago.  Drives normally with no noticeable decrease in power.  Only issue is at stop lights, it idles too slowly and the car shudders.

I'm thinking the throttle body is dirty, and the computer was reset with the battery change so it hasn't relearned to compensate yet.  

Any thoughts?  I've never actually cleaned a throttle body before.

I had a similar throttle body issue on a 2000 Camry. Cleaned the TB with Deep Creep and a toothbrush. Solved my issue.

super easy.  YouTube will help but, just undo the rubber boot snd start cleaning inside.  I wiped everything down well.

Update:

The shuddering issue corrected itself after a few days, I guess as the computer relearned as she drove.  However, I still wasn't happy so today we cleaned the throttle body.  Put it back together and it is running smoother than when we bought it.  No more shuddering at all.  

It was seriously pretty dirty.  Way dirtier than I expected it would be.

Thanks!  Much appreciated.

Glad that worked!

Now, I have a young driver who has had three rear end accidents in the past three years. The latest was yesterday and the first to be reported on insurance..got a fix for that

A bicycle.



That sucks, man.

Yep, remove all passengers, phones and texting devices from her/him. The vast majority of people drive and text now from what I see and that includes new drivers and OTR truckers.

Insurance called yesterday, $1400 damage to the F150 Platinum, more if he gets rental car. Debating just paying it as the cash isn't an issue...long term rate jump would piss me off. Still discussing with Amica.

More to the story about this kid but I'll keep that off the nets.