I have one main question but several others also. To start my 2000 3.0 4x4 flex has catalytic converters beneath the truck in the center of the vehicle. Truck has 230k and I bought it in the summer. The muffler shop told me there should be two in the front also. They refused to install a new converter because of rust on the pipe the converter attaches to. I have looked up the part and I do see that there are two catalytic converters that connect to the mainifold for a total of four. Mine does not have the two up front. Could this be stock? I mean were some made without the front catalytic converters? Because some do have the two.

Secondly, the ones beneath the truck are usted at the flange. I purchased a replacement. The pipe is rusted and I'd like to take a wheel to it and paint it with bbqer hi temp paint. I guess I'll save the question on this until I have some pics. Replacing it scares me. Muffler shop said you can't weld to rust and to buy the front ones and they would replace all together. I think I can get the old one off from the rusted flange. The rear section of stock pipe doesnt have a flange so I bought one that bolts on. I guess I need to wheel off the pipe in front of the flange and see how bad the rust is before I attempt to remove it.

It is very loud and I don't like it. Even though shop says it isn't affecting performance.

 

Shop is correct, can't weld to rusted pipe, and I think you will find its rusted all the way up, you probably won't find a strong enough section to use

When you burn a hydro-carbon(gasoline) with Oxygen(air) you get H2O(water) as a by-product, that's why you will see water dripping from tail pipes
So exhaust systems rust from the INSIDE OUT
That's why stainless steal exhausts are popular, they don't rust inside, but very expensive, lol

Yes, 3.0l Rangers came with "Y" pipes without Cats and with Cats, it depends on which STATE they were originally sold in when new

I think you can only get the ones WITH Cats now, as that will work to replace either one, i.e. it doesn't hurt to have the extra Cats, except for the wallet, lol

 

Was looking up front coverters online. Most go from 98-2000 or 2001-2004. But I have seen a few that go from 98-2001. So do you know if I can buy one that says 2001- 2004 for my 2000? Because I did see overlap with the one that says 98-2001

but I see the flange is not the same.

 

Partsgeek lists the 2001 cat and the 2000 cat as different parts. The pic however is the same part. I called them and they said the pic is correct so am I correct in assuming that the front cat from a 2001 will work on a 2000? I thought the flange was different, but maybe not. I can get the 2001 cat much cheaper. Not on partsgeek. But I think any 2001 ranger converter will fit a 2000. Especially if same L engine size. Am I correct?

Here are some pics. These are not the same converters. Not the ones on partsgeek. But are they interchangeable? The flange in these do not line up with the flange on my new rear catalytic converter for a 2000.



This is 2000

this is 2001

 

Shop installed front and rear cat. Downstream O2 was stripped so the I had them plug the hole. So two times in less than a week the truck hits the ceiling at 3000 rpm and won't go over 30. Pull over. Get back out on road. No prob. I thought first it was that the new rear converter is much smaller than the original. So I thought maybe restricted air flow. Then I remembered the sensor. It was hard wired before I had it so I bought the clip and wired it. It has two whites that are identical so I just put them to two whites. Black and grey to black and grey. Put in new sensor.
Could lack of sensor have been what was causing truck to have problems? Are the two white wires interchangeable? There was never a problem with acceleration since I bought the truck in the summer until after I had the new converters installed. Even with sensor missing I did not get any lights or chimes. It is installed now. Truck is quicker.

 

The whites are heater wires so interchangeable

Info here: https://www.fordforumsonline.com/cdn...hart-jpg.5666/

Connector wiring here: https://easyautodiagnostics.com/imag...11/image_1.jpg

Downstream O2 should not effect performance, but, if disconnected, it should have also set TWO codes, minimum, after engine was fully warmed up
It would have set "heater code" with key on, well in a minute or two, which is monitored separately and then set a no signal code after full warm up

The heaters all get 12volts with key on, this is a shared 12v wire, and each O2's heater is grounded separately in the computer, so with key on computer should see 12volts on each O2s heater ground wire
A heater is just a coil of wire, so 12v in = 12v out until computer Grounds it, and computer will test heater periodically to make sure its still getting 12volt until sensor is fully warmed up

 

I got it installed Friday. I have had no waring lights or chimes.This was without the sensor installed. Well if that wasn't the issue I don't know what changed to cause an acceleration issue. Smaller converter? Could that be it? Never had one problem til after new converter. I think compression increased. Truck got faster. I wonder if extra compression (regular compression) has uncovered another problem. Maybe the cat is too small. Above in the thread is what the stock cat looks like. The pan shaped converter. Above that is the one that I bought. Round shaped converter. It should matter for the front because that was a y pipe so even smaller. The rear was the pan shaped one. Which is now smaller and rounder.
The truck hits a spot at around 3 on the RPM gauge and it starts skipping and not going faster.

 

3,000rpms is where a REV limiter would kick in when computer thinks transmission is in Neutral(park/neutral or Clutch pedal switch closed)

If you can REV engine past 3,000 in driveway then REV limiter is not kicking in, and it should, so it is not "sensing" neutral when it should, and may be sensing Neutral when it shouldn't, like when driving

As long as the diameter of the Cat entry and exit was same size as original(or larger) then it wouldn't effect performance
You can use a vacuum gauge to test exhaust flow
Install gauge on intake
Start engine, should see about 18" at idle, raise RPMs to 2,500 approx. and hold it steady
Watch the gauge, if its slowing dropping you have clogged/restricted exhaust flow, exhaust is backing up

 

That sounds like the problem. Because the truck actually is revving at 3000 and being stifled. I don't know why it happened after the new parts rather than before. I hope they did not hit something. Maybe the truck is still adjusting? I think I have more power now that I don't have three leaky flanges. Also could be a grounding issue. I had cleaned a ground up in the engine compartment. Maybe I need to see if batt wires are connected well. I say because after I did the truck revved right out of park. But not since. Until new parts.

And Thank You !

 

I read it might be the cam sync sensor. Although it all started when I took the the ground off the front wall. I took the paint down to bare metal. I put the ground back the way it was. I blew fuse 11 I think in the process. But that day the truck revved high as I put it in gear. I thought it might stall. This was before I made sure everything was back how it was. But after that a week or two and no problem with anything at 3000 rpm. It wasn't until the day after the converters were installed that I had the problem. So far it has happened twice in less than a week. I wasn't getting a check engine light without the rear o2 sensor oddly. But it is installed now.

 

Well, I revved it in park and it hit the 3800 ceiling and that is all. The ground I talked about had a loose bolt. I'll see if that fixes it now that is tightened. I put in sensor 2 bank 1 downstream 02. I had to wire a pigtail. It was hard wired. I hope I didn't yank the wires loose from the other end when I tried to strip the ends. The light came on today. I checked the fuse. Code: Bank 1 heater circuit sensor 2. I hope I got the wiring correct. I think I did. New sensor lit up dash today though. Just the one code. After is when I checked the main ground in the engine compartment. I found the nut was not tight I moved it with my fingers. Maybe that will fix all of this. If not I messed up connecting the sensor somehow, and in addition I have a possible cam sync issue that I read is common with my model.
But it all started after the new converters were installed. Sometimes I notice when I am going uphill is when it happens. This is the same I read can happen from a bad converter. But yes the openings and pipe are the same size as the old. The filter part is smaller though.

 

​​​​​​All 1998-2000 3.0 and 4.0 came with 2 Converters on the Y-pipe

 

Heres the facts on the 1998-2000 Ford Ranger Exhaust. First, 2.4 liters dont have a Y-pipe.
There is wrong information about the 1998-2000 Ranger Exhaust everywhere on the internet.. 3.0 liter Y-pipes and 4.0 liter Y pipes ARE NOT interchangeable. There are two different Y-pipes, but It has nothing to do with California Emissions. THERE IS NO CALIFORNIA ONLY CAR. SO THEREFORE THERE ARE NO EXHAUST PARTS UNIQUE TO A CALIFORNIA EMISSION TRUCK. Ford made ONE 1998-2000 Ranger that passed ALL STATES. There also are no 4×4 specific exhausts or Y-pipes.
The difference in the 4.0 and 3.0 liter Y-pipes is the Exhaust manifold on the passenger side. To the guy who wrote earlier... The reason your Y-pipe didn't quite reach the manifold on the passenger side was because you had the 4.0 liter Y-pipe. The 4.0 is missing the last couple inches of pipe. The Exhaust manifold on the 4.0 is LONGER on the passenger side and makes up for that difference.
There are differences in the rear Converters. Some have two. Some have one, but THEY ARE ALL 36 INCHES LONG.
There are differences in the intermediate pipe between the 3 different Wheel base lengths.
The tailpipes are all the same.
​​​​​​The 2001 Y pipe has a different shaped flange than the 1998-2000.