Catalytic converter removal

[Stan48]

02 xlt 4.0l rwd.... can you cut out the catalytic converter between the o2 sensors.. if so. What catalytic converter will work in its place..... help?????

 

[Turdle]

Does this link work?

http://www.rockauto.com/en/catalog/...l+v6,1377660,exhaust,catalytic+converter,5808

Best option IMO is to find a mom and pop type exhaust shop in your area, let them hack and weld. They usually have better pricing on muffs and cats than we can get on line. The trick is finding the right shop.

 

[Tech By Trade]

I second that, Unless you are going to get a direct bolt on like a walker or oem, I would let the shop hack and weld for you.

 

[imp]

I face this dilemma right now. 154k, recurring HO2S DTC, electrically not resolvable. (After a month of fu..ing around with the harness, wiring, sensors, etc.

So, I'm ready to replace the cats. Looks like the easiest way for this old man to do it, is get the welded up one-piece "Y" setup which basically bolts in place. Bolts? The hex nuts on the flanged Y-pipe to muffler connection are rotted away to being nearly ROUND. Definitely will have to be cut off. Manifold connection? Look better, but REALLY rusted. Any suggestions REALLY appreciated! imp

 

[Stan48]

Thanks.. that's what I was thinking.... I pulled the o2 sensors on the driver's side and the sensor after the catalytic converter just happened to be stopping 2 handfuls of honeycomb from the catalytic converter.... I got it all out, but still having to force the engine to keep it running...???? It's getting plenty of fuel.. anyway, I am going to replace both cats, cuz they're bad and replace all 4 sensors and go from there.....

 

[Tech By Trade]

If you got honeycomb, your secondary sensors will be throwing a flag and your running on the stock mappings that are rich to make sure nothing burns out. Once you replace the cats expect your mileage to jump as well.

 

[imp]

If you got honeycomb, your secondary sensors will be throwing a flag and your running on the stock mappings that are rich to make sure nothing burns out. Once you replace the cats expect your mileage to jump as well.

@Tech By Trade
Been getting P0054 "HO2S Heater Resistance Bank 1 Pos. 2 every single time I climb a certain long hill coming back home. Runs, drives just fine, erase DTC, drive any length of time, no DTC until up that hill! Done this many times, just to prove it out. Completely removed the harness question by wiring 4 new conductors from the 1-2 sensor upstairs to B+, and PCM. Same thing, same DTC.

Yesterday evening I had the old lady run the engine at 2500 rpm, while I beat on the Bank 1 Cat. Not hard enough to dent it, (has a thin shield welded around it anyway), gave it maybe 12 good hits. Drove downtown today, back up that confounded hill, NO CEL!

Gimme a break! The Ford Troubleshooting Manual guides the Tech through all the possible resistance checks, voltage checks, but fails to mention Cats! Even says if harness OK, replace PCM! I have a spare PCM, BTW, and IT throws the damned DTC just the same!

Tomorrow I'm driving that frigging hill again! Then order new Y-pipe and Cats. imp

EDIT: FWIW, checked PIDS running, downstream HO2S's show NO VOLTAGE OUTPUT when started up. Takes quite awhile to appear. A guy could look, see no voltage, shut down and replace a good sensor.

 

[Tech By Trade]

Rear sensors are the old style ones with no heaters. They don't read until warm. they should sit around .6v if the cats are fine when warm. the front sensors controller your mix out of loop, the only purpose of the rears is to make sure you have your cats still. The fronts should bounce between .2 and .8 a few times a second. Most post 97 O2 systems work like this.

 

[imp]

Rear sensors are the old style ones with no heaters. They don't read until warm. they should sit around .6v if the cats are fine when warm. the front sensors controller your mix out of loop, the only purpose of the rears is to make sure you have your cats still. The fronts should bounce between .2 and .8 a few times a second. Most post 97 O2 systems work like this.

@Tech By Trade
Um, beg to differ with you. All 4 HO2S have heaters, four wires each, two to the heater element, two are the sensing leads. The heaters have resistance of about 8 Ohms, and sure enough, if you connect one to a battery, they draw around 1.4 amps when hot, a bit higher at first when cold.

EEC-IV, early 1990s did not use heated 02 sensors at all. What year the heaters appeared, I don't know, but my 2004 4.0L sure as hell as 4 of them. imp

 

[Tech By Trade]

Good to know. pretty sure the rears aren't wide band though. would make sense though. my rears locked up to .6 volts with a minute. the unheated ones take a while before they read properly and come out of loop. I guess the computer needs to know the cats are functioning right away, so it can throw a code and go into loop for no reason.