Argh... I just got my truck back from having a dent removed...

I'm driving my Dakota home, and the CEL light came on. So I brought it home, and I tested it out with my scanner... came up with a P0138, which means that the 1/2 O2 sensor high voltage.

So I wait for the truck to cool off, and I go underneath and start looking at all of the wires to each sensor. Which I have a California Emissions system with 4 O2 sensors instead of 2, which is the national standard. I noticed nothing wrong with the wires, and no grounds. So I'm figuring the sensor is bad, which going to cost me $80.

Basically, it is the sensor on the driver's side, after the cat.

I tried getting it off with a pair of Vise-Grips, but it wouldn't budge. So I've got it sitting there with PB Blaster on it... and a lot of it.

My question is, do you think the cat is bad? Or the sensor just decided to die?

Mind you it's got 108k on the clock...

 

its a dodge...at 108k....time for a trade in!!

 

You asked for that............

 

108k and factory O2 sensor consider yourself lucky. i've sold them for vehicles with a lot less miles them that.
oh and the 4 vs 2 it's just about everywhere's emissions now.

 

Well, good news... I got the old O2 out, and it only cost me $70 for a Bosch replacement.

I'll post a picture of the old and the new.

I reset the ECU, and drove it 6 miles, mixed driving to for the close-loop, and no problems so far. I'm letting it sit with the hood open with a commercial floor blower hanging on a beam blowing cold air at it.

I just want to make sure it won't kick on after another driving cycle, because it came back on today after I reset it yesterday, from a new driving cycle. So I want to do a complete cycle from open loop to closed loop to make sure everything is working ok.

The old sensor was BAD. There was actually rust on the sensor it self... not too much soot though.

 

Well, I took the blower off of it, I kicked it off, registered as a cold start, and I took off... got it on the highway for about 3 miles doing 70 mph and some mixed driving, totalling about 8.5 miles... so I got it up to operating temp and it worked without a problem.

So I had a bad sensor....

Now I can sit back, grill some burgers and get me some beer.

After I eat, I'll post the pics..

 

Well, here is the old o2 sensor:



Here is the new o2 sensor (it's a Bosch):


(Notice how clean it is under there... EVERYTHING is clean!)

I took it out for another joy ride, and it's mean running machine now... sounds great too and I notice that the rpms stopped fluctuating at a warmed up idle!