5.9 ltr O2 Sensor Location(s)

OK-
Part II of a previous thread on oxygen sensors... I've purchased a Bosch replacement "Bank1/Sensor1" from a previous trouble code (P0139). My local NAPA counter guy told me this truck has three O2 sensors, left side (driver), right side (pass.), and catalytic converter. After crawling under and in the engine compartment, I can only find two sensors. One is located directly in front (upstream) of the converter and the other in directly behinid (downstream) of the cat. coverter. The NAPA guy thought there should be one on the drivers side exhaust manifold and one on the passengers side manifold, in addition to one downstream of the converter. Anybody know where my mystery "sensor 1" is located?

Your advice is appreciated...keep it comming

As far as I know the 1st sensor IS the one that's upstream of the cat. I've never heard of 3 sensors on any 360's. And I never believe anything an autoparts store counter guy says anyway. 99% of teh time they have no clue what they're talking about.

Yeah-
I know what you mean about taking advice, but you'd think with the computers they have now-a-days, there would be less room for mistakes...?!

Thanks for the input. I'll let you know how it goes.

This post should help you http://www.dodgetalk.com/forums/showthread.php?t=19302

Get the front sensor for the right side cause the wire is longer. The left should be the smae sensor only with a shorter wire.

Originally Posted by spirit-dodge

This post should help you http://www.dodgetalk.com/forums/showthread.php?t=19302

Get the front sensor for the right side cause the wire is longer. The left should be the smae sensor only with a shorter wire.

I just read through that and now you've got me all confused. I dont' think there's 2 upstream ones on my 02 360, but I didn't look at the y-pipe on the drivers side, I guess I need to do that. But in your last post of that other thread you say 97-99 with 5.2's have 2 upstreams. My '97 only had one upstream.

twite, what year is your Ram? The O2 set ups are different from year to year. My 96' only has 2. One pre and pne post-cat. My buddies 2000 has 3 like the parts guy was telling you. So it just depends on your year of truck.

I should have pasted the E-mail I sent him. So here it is

> I have a Dodge Ram 4X4 '98 5.2 and would like to replace the pre-cat sensors. I have only one at the front of the cat. Could you please find the part #.




Got this from them

Yes, it's a bit confusing that our website shows a left and a right. I've run into this before, problem is all of my catalogs show that the '97-'99 models with the 5.2L have two in the upstream location. I usually just recommend Walker's 250-24080 which is listed as the right side sensor. It has the same connector as the one listed as the left side, just with a longer wire. I'm confident that it will work just fine in your '98. Feel free to call or write with any other concerns and thanks for your interest.

Mike Carter
------------
Auto Medic Supply
27500 Cumberland Rd.
Tehachapi, CA 93561
1-866-441-7039


I've seen alot of post here where trucks only had one upstream sensor so from that and the E-mail from
https://www.automedicsupply.com/index.php I would say get the right side with the longer wire.

I just checked and tried to re-verify my findings- I have a 2001 ram w/ 5.9 ltr engine. I can only find two(2) oxygen sensors - one directly in front, and the other directly behind the converter...several people have told me I have three sensors on this truck, but I'll be damned if I can figure out where #3 is!

Gouge-
I just checked your link to a previous thread on O2 sensors....now I'm really confused.
Speaking of wires - the wiring from my pre-cat and post-cat O2 sensors travel up on top of the transfer case and dissapear from view. Is it acceptable just to cut the OEM wires near the sensor and splice in the new wires from the new sensor, or should the whole O2 assembly be removed as a complete unit? If so, is there a plug or some type of connector on top of the transfer case that I'm not seeing?

I've got several good quality digital pix of this mytery O2 sensor situation... I'm just trying to figure out how to post them here... stand by...they should be attached.

As you can see, there are no O2 sensors apparent on the dirvers side or passengers side exhaust manifolds. Only one in front and one immediately behind the catalytic converter.
The new Bosch sensor I purchased at NAPA looks identical to both of these sensors. My trouble code indicates "Bank1 Sensor1 High Voltage"... do I assume the "front" sensor is number one?

I have a 98 ram with the 5.9. There are only two sensors on it. One right where both pipes come into the cat, and one about a foot behind the cat. This is the only two that there are. They are both different. I would not go with the Bosch sensor, because they don't work very well with Dodges. I tried this, and then went to the dealer and got one, and everything is working great. Hope this helps.

I replaced the "after converter" sensor when the check engine light came on. What a bi*ch trying to unscrew it.

Then I replaced the converter a week later. And wanted to replace the "before converter" sensor. I went to NAPA and he said the same thing about passenger or driver side. One was over 70.00 bucks and the other was over50.00 bucks. I bought the higher one, and noticed that the plug had the notch off slightly, but the wire length was the same. So I go back to NAPA, return it for the shorter wire that HAS the notch in the same spot as the old one. When I showed it to the muffler guy putting the new converter on, he said that will never reach. So, I just ended up putting the old sensor back in the "before the converter" spot.

Anybody replacing the upstream sensor, check the notch location with the old one, and see for yourself !