2002 4 Cyl Highlander - problem idling/choking off

[JDubbs]

Need some diagnosis help here.

My '02 4 cyl Highlander(171k miles) has been running great, but occasionally had an issue w/ starting, idling too slow for a minute and then shutting off.

It's gotten considerably worse in the last couple of weeks and today, unless I keep my foot on the gas, it will choke down...even when I'm driving.

Got the oil changed today and the mechanic suspects the Cat is clogged up, but it accelerates just fine and cruises great w/ no noticeable power loss...which makes me think it might be something else.

Any ideas? The only engine codes are for the Oxygen sensors in the Cat, so that may be telling, but if anyone else has had a similar problem, I'd love to hear.

Thanks!

 

[Sam Stewart]

Check the idle air control valve. It's attached to the bottom of the throttle body. They get sticky sometimes and won't let the vehicle idle correctly. The easiest way to check it is to get the car running and tap the throttle body. If the idle changes, that's most likely you're culprit.