DodgeTalk Forum banner

Status
Not open for further replies.
1 - 13 of 13 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
Should vehicles using 2 up and 2 downstreams have the ups or downs both replaced at the same time in a high mileage vehicle (>100k miles)?

Thanks,
Flickit
 

·
Registered
Joined
·
10 Posts
Discussion Starter #3
Thanks dodgefan360!

I removed the left side and found it was cracked so I replaced it with a universal from Bosch. Am going to order the right-side as it seems only to be available from Dodge. Funny thing is many "experts" say to replace them only if you have an engine light or failure code but they don't seem to understand that they do age!

Flickit
 

·
Registered
Joined
·
344 Posts
If your consuming fluids I'd get them all changed. Otherwise, just the forward ones will do.
The downstream O2's do nothing more than tell the computer if the cat is still working correctly. The upstream one is used to calibrate the fuel mixture.

Explain how a bad downstream O2 sensor would cause fluids to be 'consumed'?
 

·
Registered
Joined
·
827 Posts
bowhunter.....that may have and was true at one point about downstreams just being "monitors".....isn't any more...........upstreams provide short term changes via the pcm......pcm also uses downstream more like a long term trim........general mechanical condition..........lower compression burning oil or antifreeze...........most problems occur when ther's an exhaust leak before the downstream sensor.........extra oxygen the pcm sees missfires basically and starts pulling away fuel........or shorted downstreams cause the pcm to overly richen the mixture.........either case will not set a code at some times
 

·
Registered
Joined
·
344 Posts
Ahh, Thanks for the info Gramol. I stand corrected.
 

·
Registered
Joined
·
27 Posts
My 2002 Dakota Sport when from getting 19/20 mpg to getting 13/14 and this happened almost overnight.

When I take it to the dealer, it shows that no codes, the service department seems baffled.

Could an O2 sensor be the problem and could it be broken without blowing a code?

The only thing else I can think of is a faulty air sensor.
 

·
01RC2WD4.75SPD
Joined
·
790 Posts
red dakota sport, could be anything especially if it "happened overnight" check your air filter, is there something restricting it? It will take a few days for a code to be popped. Exhaust plugged up? If there is something wrong trust the computer it will get you a code.

flickit, i wouldnt change the other sensors unless you geta real deal on them or unless they are broke, save your money and wait till they go.
 

·
Registered
Joined
·
27 Posts
Here's a list of what I've done thus far.

1. Changed the air filter
2. 2 stage fuel system cleaning
3. New plugs and wires (they needed to be changed just due to wear)
4. New fan clutch
5. All the scheduled maintenance
6. Reset using the key/bump starting method
7. Had the fuel system/pump checked
8. Nothing outstanding on the dyno.

I just find it strange that there's such a mystery surrounding this mileage issue. I mean the dealers have basically shrugged his shoulders on this and have never heard of such a problem yet I know 3 people who own Rams who have the same problem.

I just don't think its breathing enough and considering I had my lights conk out on a dark road, I'm just not a fan of Dodge/Mercedes electrical engineering.

Besdies O2 sensors aren't there also air sensors at the point where they used to put a carborator before fuel injection?

Also about how long does it take to change the upstream O2 sensor?
 

·
Registered
Joined
·
144 Posts
Here's a list of what I've done thus far.

1. Changed the air filter
2. 2 stage fuel system cleaning
3. New plugs and wires (they needed to be changed just due to wear)
4. New fan clutch
5. All the scheduled maintenance
6. Reset using the key/bump starting method
7. Had the fuel system/pump checked
8. Nothing outstanding on the dyno.

I just find it strange that there's such a mystery surrounding this mileage issue. I mean the dealers have basically shrugged his shoulders on this and have never heard of such a problem yet I know 3 people who own Rams who have the same problem.

I just don't think its breathing enough and considering I had my lights conk out on a dark road, I'm just not a fan of Dodge/Mercedes electrical engineering.

Besdies O2 sensors aren't there also air sensors at the point where they used to put a carborator before fuel injection?

Also about how long does it take to change the upstream O2 sensor?

Number 6, What exactly are you resetting and how is it done? Reset the computer, timing, what?
 

·
Registered
Joined
·
27 Posts
I did the reset due to two issues.

1. There was a "bogging" issue when I started the truck up that got worse in cold or damp weather. The engine would rev like crazy, but it had no power.

2. The ATM got messed up. I put on my fog light one night and all the lights went out as I was driving home one night. I unplugged the module, waited, hooked it back up and used the key method of resetting the truck.

My last fillup yesterday, I got 10.8 mpg. The fillup before that I got 15.6 mpg. (I was getting 20 right up until November of 2007 including the previous winters )I took it back to the dealer and he's gonna get his voodoo shaman right on it.
 

·
Registered
Joined
·
344 Posts
"1. There was a "bogging" issue when I started the truck up that got worse in cold or damp weather. The engine would rev like crazy, but it had no power."

This dosent sound like bogging, instead Transmission slippage. IF you tranny is going bad it could very well explain your poor gas mileage.

Whats an ATM?
 

·
Registered
Joined
·
27 Posts
I'm not sure about the tranny. They reset the pcm and thus far the truck is working better. I'm not sure yet about any gas mileage improvement. I'll talk to the dealer about the tranny, but wouldn't that blow a code?

The ATM auto timing module. Could have the name a bit wrong. Its the box that to the left of the peddles. Most of the electrical runs thru it and it handles the dimming and the delay when the lights turn off.
 
1 - 13 of 13 Posts
Status
Not open for further replies.
Top