Car sets code P0172, it has rough idle sometimes, replaced o2 front sensor, plugs, tps, checked egr. There is a sensor below the tps that has a 4 wire plug, I unpluged it while running rough it did not effect the way it runs?
The other sensor is should be idle air control? Clean the throttle-body and idle air system.
November, 17, 2011 AT 10:44 PM
It's probably the idle control motor. Unplugging it would hold it in it's current position but it would be unable to compensate idle speed when needed.
November, 18, 2011 AT 12:19 AM
Find the idle air control valve and clean it and see what happens
November, 21, 2011 AT 1:30 AM
I was able to clean the I a c, car starts up great, as soon has I push the throttle then it starts it runs rough, turn car off crank again runs great. Any ideas
November, 21, 2011 AT 5:34 PM
Po172 is bank 1 one sensor 1, system rich. In your first post, you said intermittent rough idle. When you open the throttle, it should bypass the iac. I'd use and check fuel pressure, for a start. Not only check for correct pressure, check that the pressure doesn't drop like a rock, with everything off. You might force the system lean, if possible, to see if 02 sensor will react.
August, 12, 2012 AT 4:20 PM
I had a car in my shop with the same problem. It turned out to be the after cat o2 sensor was stuck rich at.910 ma. It was not told to me by the customer first but, when she had the oil changed her oil guys noticed the un-plugged o2 sensor. They decided to plug it in and 2 days later her cel turned on with p0172. I replaced both and solved the problem.
August, 12, 2012 AT 4:24 PM
He asked the question nearly a year ago. I think he might have it resolved by now.
August, 12, 2012 AT 9:40 PM
Yeah duh teach me to look at dates haha. Oh well I was in the middle of looking at some other problem and thats what happened honest