So I don't have the Califonia emissions, but I am trying to diagnose a low power at hwy speeds during towing. Low speeds seem ok but cruising speeds and low fuel economy are an issue.


Anyway, I've put in 4.10 gears with 33" tires and after break in hooked the bumper pull travel trailer up and took a ride. The trailer weighs 8,000 lbs (verified) and is 26' long. New plugs, FS fluids, haven't replaced the wires (were after market when I bought her and look good) but over all runnin ok from what I can tell.

Anyway, trying to run in Over Drive but she feels like she can't do it and wants to run in 3rd? Fuel mileage is 5.23 mpg at 65 mph?

So thinkin O2 sensors. Got under her and I only have 2? Both up stream????? CAT's go directly into the muffler and tail pipe out. Looks all OEM, however 2 1/2" in X 2, and 3" out single. But no Post O2 sensor?????? Remember these are towing numbers. Regular numbers are 10 hwy and 6-8 city unloaded.

When I first got the truck she lugged but got an average of 7.5 mpg's at 65-70 MPH. Then she fail to 5 mpg's and just always lugged so I installed 4.10's thinkin she'd wake up. Well she feels awake but still lagging especially at hwy speeds?

Thinking about pullin the O2 sensors (concitering I can only find 2) and trying first to clean them up with a lil emery cloth, burn em with a propane torch and reinstall? No codes right now and smooth running?????


Comments welcome?

 

you have O/D off right? if you tow with O/D it can eventually kill the tranny....

 

Sounds stock to me one header into each CAT both CATs into muffler then out.
I went out and found the 2 preCAT O2's on mine but didn't see any post CAT sensors... Interesting, it's DARK here so I'll check again tommorrow if I can get out of work at a reasonable time.
But I had both CATs plug on mine back in 03 and it had a hard time shifting into OD, but it came with PING.
I'll let you know what I find

 

I have a 47RE trans, not the 46RE like yours.

The reason it kills the trans is because of excessive shifting do to the lack of power and the heat caused by shifting. Unlike the 5.9L motor with the 46RE, the V10 with a heavier built 47RE trans has more power and a better built trans. With a V10 it falls into a different category. In your manual it tells you to lock it out during heavy towing, but not in ours because it's built for it. There is the lock up Torque converter however, so during hills and traffic (in town) I lock it.

Mine is stock engine built other than the normal tweaks, K&N, and a built trans. She runs good and even took us on a 2000 mile trip to Cali last August, but really sweat it on the way back (which was strange). I did have a head wind (but not both days) and 100 F temps but at worst ran in 3rd at speeds down to 45 mph full throttle on very slight inclines and 50-60 flat ground. Now this was with the 3.55's and now I have the 4.10's, but down low I have the grunt, but the heigher the speed, the lower the power.

I have 1 pipe from each manifold and around the middle of the trans there is a O2 sensor on each pipe. Then both those pipes come together about the end of the T-case and there is 2 CAT's sitting side-by-side on end. Then the go directly into the muffler (dual input muffler). CAT is Dealer Part # O 746ACW902. Well it looks like an "O" before the number separate from it. The CAT's both have the inputs of the air pump from the front that splits "Y" into both CAT's.

Anyway, it has the dual input 2 1/2" and the muffler is long and round (barrel type) with dealer numbers (didn't write those down). Output appears like 3" to tail pipe, but again no post CAT O2?


There's no doubt that it looks OEM cause of the rust. Pipes look good still however. Does yours have 2 O2 sensors before CAT? I'll have to take a closer look at mine to see if I have 2 pre CAT's.

 

I just rolled under my 01 and it's exactly as you described your setup. I only have pre-cat O2 sensors, no post cat. There's like 1" of pipe between the cat and the dual inlet muffler. Everything back to the muffler looks to be original (only 87k on the truck so I can believe it), the muffler and tail pipe are new.

 

sounds like your cats need to be changed hookup your trailer and take it for a quick drive with the o2 sensors ziptied out of the way if it has more power with them out it is either cats or muffler plugged or both. Dont run like this too long as them O2 sensors are used for air to fuel.

 

You mean pull the O2 sensors completely out so that some exhaust will make it through the thread holes, or just un-hook the harnesses and leave them in.


Jimy<----- Ya there's just like 1 inch of piping between the muffler and CAT's......LOL


I'm under an assumption that with the air injected via the air pump directly into the CAT's, that no post O2 sensor is needed?

 

Yeah take the sensor out of the hole...leave them plugged in though, the exhaust will come out those holes and if you gain power then you know that something is clogged down the line, a clogged cat can severly limit power and will be noticed at first under load

 

Yeah the 2 pre cat are on the pipes leading too the CAT right about even with the tranny belly pan.

Went out to mine, and only have the pre CAT. Parts manual verifies this and has several revisions in the 2001 model year.
Cali emisions revised as up to 2/21/00 and after 2/21/00, for the post CAT sensor
Cali and fed revised before and after 6/26/00 for the pre CAT sensor
(the above info is for anyone searching 2001 in the future)


The 2001 year with CA emmisions has 2 pre and 1 post
Federal emmisions has 2 pre only.

So I checked 1999, V10 not even listed and all gas engines are listed as having 1 pre 1 post sensor.

SOOOOO I checked the 2000 and found 2 pre and 1 post sensor (doesn't say **** about Cali or not)
So dodge it seems was playing around QUITE a bit with the CATs and sensors.

Anyway back on subject like I said I had a issue shifting from 3-4 and it had the mother of all PING but only if I pushed the pedal to the floor. I only noticed it while trying to merge onto highways, not really sure if it hesitated while driving normal through the ranges.
It was awhile back, dealer first flashed the PCM, then found it was the CATs were plugged and or collapsing

EDIT here was the TSB on the 3-4 shift issue that the dealer flashed, it appears it was only 00-01 though http://dodgeram.info/tsb/2002/18-006-02.htm

 

Makes sense. I'll pull em and see what happens.


I was thinkin, I might just remove the CAT's and air pump lines and gut the air pump concerting I don't live in an emissions county. Just put in a lil new pipe and replace the muffler with a MagnaFlow big black series muffler and call it a day......

Without a Post O2 sensor, well why not? It wont change anything anyway......