O2 sensor knocking-(I’ve attached OB2 scanner readings for possible help)

I noticed last week that my truck started to knock during more so than just lifters cycling as it’s always done. I could hear it sounded as it was coming directly underneath my driver seat once the began to try and diagnose. My truck now has 168k miles on it and I’ve owned it since new. Never changed o2 sensors in it or ever for that matter but I’ve changed spark plugs and done all the regular maintenance on my truck since I’ve owned it. When using my scan tool I’m getting this but no code is being triggered in the dash board. Not for sure but i believe the bad sensor is the “before CAT” sensor pretty much located directly underneath driver seat… please correct me on that bc i may have bought the wrong replacement. Ordered the “downstream right” NTK…
Also I’ve cleaned mass air flow sensor with Crc MAF cleanser and I’ve followed the guide on cleansing the throttle body and changed my air filter within the last couple weeks.. just as an fyi for diagnosing the issue. I’ve also checked pulleys for being loose. It doesn’t do this always. Just intermittently
also does anybody know what the evaporator failed may be? Would this have to do with O2 or CAT converter as well?

 

While I don’t know, before you go replacing parts, I would warn you to fully understand the tests being performed, as some are performed only under certain conditions. “Not passed” may not mean “failed”. But a tech here will probably be able to better help.
Also, I doubt an O2 sensor is knocking,,, the exhaust system maybe.

 

Also here is what I’m getting at 60mph highway driving currently

 

Thanks for the response and It may not be knocking but I can tell you it’s coming from the exact area where the o2 sensor is before the catalytic converter… hopefully it’s not the CAT… I’ve heard of o2 sensors making a knocking sound but maybe I heard bad info?? What gets me is it runs as good as ever bessides idling..

 

Noise can travel in crazy ways. Might think it’s one place but really it’s coming from somewhere else. These cars are so advanced today if the computer seen something that’s out of spec I’d think it would throw an engine light quickly . Just my 2 cents

 

Off topic, but what app are you using for all those read outs? That's really good information.
Do you need a Bluetooth dongle attached to the OBDII as well?

 

This was 2 weeks ago when I went through a mud puddle and got surprised mid way through that it had a 3.5 ft puddle so I know several things were exposed to muddy water. I came home and cleaned it very thoroughly after the trip was over and nothing seemed abnormal until the knock started at idle. I do have the rear arb diff breather kit as well as trd engine and RCI transmission skids

 

It’s a VEEPEAK ob2 dongle I have attached at all times it’s very helpful just wish I understood the info a little more thoroughly

 

I totally agree that you would think it’d throw a code. However around 150k miles I had a master cylinder rear seal leaking all into my booster and I never got a code just noticed my brake pedal being squishy going all the way to the floor one morning then had to top off fluid reservoir once a day. Looked for a week straight trying to find leak and couldn’t so I ordered a master cylinder and lo and behold the booster was full of fluid whenever I got it off. I used my handy Holt industries harbor freight fluid extractor and extracted all the fluid from the booster and installed MC and everything at this moment point with the brakes seem perfect. Just have this knock underneath and code reading about failed o2 evaporator and catalyst. I know I got some brake fluid underneath on some of the parts around this area the noise is coming from. I read brake fluid is some pretty toxic stuff too so was thinking possibly it’s eaten into something

 

Here are some pics of where the knock is coming from maybe this will help. It looks like it connects to a connection on the atf system.. if you can identify it for me I’d appreciate it

 

Could be the inside of the cat coming apart. I mean you do have lot of miles man or possibly a hear shield broken and banging around

 

Pretty positive I’ve found the culprit and hopefully it’s not been like this long. Seems to be running great besides that intermittent knock. I just changed the oil after discovering this about an hour ago and use sea foam regularly maybe it’s cleared and h20 that may got in…
It wasn’t broken off completely when I found it but it was definitely cracked and about ready to break off though. I pulled the hose and discovered it. I started to JB WELD it for temp fix then Luckily I remembered that I kept my original intake and installed it while I wait on HPS to have their silicone back in stock bc I’m not buying another plastic one for this reason.. DAMNIT! anyway I wasted time and bought o2 sensors I doubt I even need

 

That’s why I’ll only run stock oem intake or TRD intake

 

This was actually TRD intake that cracked. Been on my truck for 80k now

 

Update installed air ratio sensors today and o2 sensors and now everything seems to be “passing” so maybe they were needed and due. Didn’t hurt anyway to freshen them but can’t really feel much of a difference in driving it yet

 

Nice thread.