2001 Dak with the 4.7L. Yesterday I got a CEL with p0135 code. Engine runs fine still. Looking to replace both with either these http://www.rockauto.com/catalog/more...569&cc=1430082 or http://www.rockauto.com/catalog/more...580&cc=1430082. Quite a price a difference, any reason why I shouldn't go with the Denso?

Also I am concerned that the issue isn't actually the sensor. Two weeks ago the upper radiator hose busted and the truck overheated. Should I be concerned that a head or intake has warped and antifreeze is getting into the cylinder, and that is what is actually causing the CEL? If I pulled a sensor is there anything I can look for to see if this happening? Oil looks ok, but I was gonna do an oil change when I replace the sensors and send a sample to Blackstone. Another issue I have is an exhaust manifold leak for a year or so, haven't fixed it yet because I fear it has the dreaded broken bolts, and no drivability issues so why bother. Anything I can do to see if this is the cause of the CEL?

 

Denso or NTK are both fine. Your truck could have come OEM with either.

Don't bother pulling the sensor for a visual check. You really can't tell. But, if you pull the spark plugs THEY can tell you if you have a head gasket leak. Look for one really clean, as in "steam" cleaned.

How bad was the overheat?

It could just be coincidence the O2 sensor failed now.

Anytime you overheat, change the oil.

 

These trucks are very picky with O2 sensors. I would stick with OEM which are NGK/NTK's. People have reported a lot of problems with other brands such as Bosch.

You can always swap the O2 sensors and see if the code follows. That'll help narrow it down if the sensor is the culprit or if its something else.

 

The 4.7 is so notorious about blowing heads at an overheat I wonder why so many people with the 4.7 are not just constantly checking their cooling system and keeping it in top condition new hoses and such every 5 years or so its cheap insurance.

A new engine is expensive in this bad economy who wants that

 

i would be more than concerned with the overheating like 98 said^ they are notorious for blowing head gaskets i had an 02 and i couldnt figure out what was causing the over heating everytime i would change something it would trick me into thinking it was fixed soo keep an eye on that temp gauge cuz you'll be sorry if you dont

 

I was towing when the hose blew, so at first I just thought it was overheating due to the load. Pulled over, kept the engine and ran it about 1.5k rpm to cool it, then noticed the steam coming out from the hood. Once I saw the split hose I knew it was screwed so I shut off the engine. Probably ran for a minute or two overheated. Granted the truck has 178k and was probably going to be replaced by a new Canyon this fall, but it has been such a good truck (and I've taken care of it) that I was hoping to sell it to a buddy for a work truck or for his son.

 

well if you replace the hose and cross your fingers that it doesnt keep overheating it might be fine and if you havent blown a head gasket already i could be wrong but i wouldnt give up on the truck

 

It's never overheated except when the hose blew. Most I've ever seen is about 65% on the temp gauge on a hot day hauling dirtbikes in the mountains. I might replace the lower hose and thermostat while I'm doing it, or not...fall isn't that far away and the new Canyon will be here.