O2 sensors

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Jul 11, 2008 | 02:38 PM

Roll Tide

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O2 sensors

I have a 96 explorer 4x4 v6 and am getting three codes (P0135, P0141, P0155) about the O2 sensors. I can clear them and a little while later they're back and all at the same time. I find it hard to believe they would all go bad at the same time but I guess anything can happen. I did have another code that has not come back on yet and it was something about the engine coolant. I forgot to write down the code.

Jul 11, 2008 | 03:22 PM

Bear River

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Have you checked for intake leaks? Who says that you have an O2 sensor problem. Those codes are common when the upper intake manifold starts leaking.

Jul 11, 2008 | 03:53 PM

Roll Tide

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I checked the codes and it said it was the Heated O2 sensor blah blah blah. Really don't remember it word for word.

Haven't checked for leaks but I will. Do you mean the hoses and/or the intake itself? Haven't heard any leaks. Would a bad catalytic converter cause these codes?

Thanks,
Steve

Jul 11, 2008 | 04:02 PM

Roll Tide

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Just went outside and cranked it up to check for leaks and heard an odd noise. When I cranked it up it started making a howling noise. I could put my hand on the intake tube and feel the vibration of the noise. I disconnected the air filter and it got louder and was definitely coming from the intake tube. Patted the gas one good time and it stopped. Something funny's going here.

Thanks,
Steve

Jul 12, 2008 | 06:09 PM

aquanaut20

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Quote:

Originally Posted by Roll Tide

Thanks,
Steve

That is a sticky IAC valve, clean or replace.

Jul 13, 2008 | 12:40 AM

Bear River

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No, a bad cat will not cause O2 codes, though bad O2 sensors can cause a bad cat. O2 sensors should be replaced every 80,000 miles. The downstream O2 sensors (the ones behind the cat) do not need to be replaced unless they set a code.

A bad IAC valve and a bad MAF sensor can both cause strange noises in the intake. I would check the IAC valve. At least try cleaning it.

Jul 13, 2008 | 07:27 PM

BJWinter

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From: Kansas City, MO

The howl is definitely the IAC. I chased that noise for a good month before I figured it out. Scary, scary sound. I would also reccomend checking for an upper intake leak. I was throwing those same codes, replaced the O2 sensors, and the codes still showed up. Haven't had a problem since I replace the intake gasket. Seems to be a pretty common problem with this engine.