5 Catalytic Converters?!? What Was Ford Thinking?!?

[Winblad]

I chased problems with my 2003 Ford Ranger XL 3.0 for a long time and replaced so many parts, to deal with it running so badly until it barely could drive at all, spending literally thousands of dollars to get it running again. I'm hoping that by sharing this, it might help other owners of Ford Rangers.

I purchased my Ranger from someone who bought it at auction from a local city, where it had been used and maintained well, with about 108k miles in 2016. I immediately had the transmission fuild and filter handled before even driving it much. It drove great for a few years, changing the oil and filter regularly. Then it started running rough, so I went for the basics like spark plugs and wires. More problems started up so I ended up changing out the fuel pump and filter, MAF, compensation gear, O2 sensors and even the PCM (and more).

Nothing was resolving it running so sluggishly at higher RPMs so I took it to a completely different local auto repair shop that was well reviewed, and they told me there was a clogged catalytic converter on the driver's side. They said they were able to see huge back pressure after removing the O2 sensor after the exhaust manifold, and sent me to a local muffler specialist, where I had the Ranger towed to. They contacted me and said there were 3 clogged catalytic converters out of the 5 that were on the vehicle.

FIVE CATALYTIC CONVERTERS?!? WTF was Ford thinking? This feels like a failed experiment gone horribly wrong by Ford.

I got the three cats replaced at significant expense and drive it around for about 2 weeks, then it began running even more rough than before, barely drivable, so I had to have it towed back home. There were a series of ten error codes being thrown up through the OBD, mostly related to the transmission and torque converter. I was referred to a transmission specialist, and they ended up saying it wasn't the transmission but more likely an electrical supply problem and something grounding out the PCM power that was causing the codes.

I was referred to another local auto repair that specialized in electrical and other more detailed problems, by the shop who had diagnosed the cat issue originally. They said they were resistant to even work on the vehicle after so many hands had been on it, quoting me $1,000 just for diagnostics. I had already dropped so much into the Ranger that I felt it was cheaper than replacing it, after everything that had already been done on it (and might have to be done on any other used Ranger I might purchase).

FINALLY! I got a call from the last repair shop after about 4 hours, saying my Ranger was fixed. A 20 amp fuse kept blowing, so they traced the wiring with the wiring diagram and discovered two wires coming from the transmission to the PCM that were melted and fused together, near one of the cats. Evidently, they must have dropped down when the 3 cats were being replaced, and once those were repaired, it ran fine.

After so many problems and chasing just about everything imaginable, I was relieved it appeared to finally be back on the road again, but couldn't believe Ford felt that five catalytic converters on a 3.0 V6 Ford Ranger was a good idea. Almost everyone I spoke or met with looked at me like I was crazy when I told them there are 5 cats, including a smog testing station who pushed a rolling mirror underneath the Ranger, then look it up on the computer to confirm it, saying that was crazy.

If anything ever happens again, I was told that maybe I ought to cut out any bad cats and just go with one to pass the smog test, if something goes wrong in the future with the other two. Has anyone else experienced anything like this, and have ended up reducing the number of cats? I'm interested in knowing if lots of Ranger owners have had similar problems and come up with unique solutions.

I want to add that I have never recommended or insinuated that removal of all catalytic coverters would be acceptable. A mechanic suggested that it could be possible to reduce the number of cats and still have it functioning properly, although the replacement cats might have to be a different size and capability to be in compliance with CA state and federal laws regarding emissions.

Additional Note: Many have commented about there not actually being 5 catalytic converters, but even the service manual shows all five, confirmed by each person at an automotive servicing facility who couldn't believe it when I told them how many there were. Due to what we know now about how efficient one or two catalytic converters are with even larger vehicles, automotive experts have indicated to me that at some point in the near future it may become necessary to upgrade from the 5 smaller cats or deprecate to 3, which would not be illegal based on what we know now and the vehicle meets all necessary emission standards. This is not to say that it wouldn't also require some reprogramming, so it would be somewhat similar to partial engine swap, on the basis of the emission system update/upgrade to newer technologies and current knowledge base.

I'm not sure if I would ever do it, yet I heard from one person that someone did change to fewer cats, dropped from five to three of higher rating, reprogrammed the PCM accordingly, and it came in well below CA emission limits legally. Then again, I understand that was a consumer passenger registered vehicle that wasn't passing smog beforehand and my Ranger is registered as a commercial vehicle, so that wouldn't apply for me.

 

[85_Ranger4x4]

If the truck is running correctly they will last darn near forever. My last F-150 had four and had 200k when I sold it, the 17 years and 175k miles I had it for I never had an issue.

Also as a reminder:

Removing the catalytic converter(s) is illegal. Regardless of the emissions laws in your particular state, it is against Federal law. The Ranger Station does not endorse or recommend removing the catalytic converter. Threads or posts advising removal of the catalytic converter may be locked or removed.

 

[Shran]

Were there actually 5 on it? Some vehicles had pre-cats - basically a cat with nothing in it, then the converter itself. Thought I hit a gold mine the first time I scrapped a car with those in it.

I have never had issues with cats on old Rangers. I inspected the one in my '88 when I was putting a new muffler on and it looked great, and that truck definitely has never run right. I think sometime in the mid-late 90's, technology & emissions laws crashed into each other and it resulted in cats that clog up easier. In my experience there was a period of about 10 years starting in about the mid 80's where they just very seldom have any issues.

I'd also be curious to see how much cleaner the exhaust is on a truck with 5 converters vs the rest of us that might have one or two at most.

 

[19Walt93]

I worked at a dealer form 1975 until 2017, I've never seen more than 4 cats on a vehicle and that was on Mustang GT's with dual exhaust. Two in the Y pipe and one behind them is the usual setup.

 

[WutUp Clegg]

there are 2 or 3. I have never heard of 5.

 

[JoshT]

My eyes aren't working well enough to read the OP on my phone right now, but the poll is slightly larger and I can read that.

I'll tell you, those poll options from a new member (Cali based at that) scream "hi, I'm from the EPA, tell me all your secrets."

 

[bobbywalter]

many big v engines have 4 post 2007.


an o3 small 6 with 5 hmmmm .

the rangers actually just got left and right later on. i have seen some with post cats. not sure on year though.


lets see your door sticker and engine calibration.

 

[bobbywalter]

where is the what is a cat option?

 

[lil_Blue_Ford]

Never seen a Ranger with 5 cats. Unless they were the furry 4-legged kind.

A bunch of Rangers got loaded down with pre-cats. They are the ones on the Y-pipe. There may be more. Usually what I’ve seen is a pair of pre-cats on the Y-pipe and a single cat on the exhaust. Sometimes I’ve seen two after the Y-pipe but I’ve never cut it apart and checked if one is a pre-cat or not. I don’t see a problem eliminating pre-cats since there’s really nothing there, and most of the header options eliminate them.

Of course, when California is involved, all bets are off…

 

[scotts90ranger]

If there's more than one per bank of cylinders it's one coarse brick first to burn off the hydrocarbons then a second to deal with the CO and NOx more that's bigger with a finer mesh... My V8 Explorers have two per bank then a giant muffler then a resonator, my '97 Ranger just has the one cat that has two bricks in series in it.

Misfires are the #1 cause of catalytic converter failure, fouled or just bad spark plugs or wires will let an unburnt air fuel mixture past the engine that will burn somewhere and since that's the job of the catalytic converters they'll go exothermic and melt into a wad somewhere around 850C if you're not too lucky and keep going... sometimes that will blow out the back and into the muffler or something but sometimes it'll just melt into a solid chunk of ceramic...

It's just one of the consequences of the times, that was an era before misfire diagnostics were too accurate and if there and ignored you'll get that unfortunately...

 

[MaicoDoug]

Winbald I hope you have that Ranger running correctly. I have inspected most of the wiring under my ride and installed some extra insulation in that exact area due to what I figured was going to be a hot & exposed area. So thanks for the heads up for sure. Used some fiberglass tape and a chunk of hose split down the length.

Received a Locktite evaluation kit once. It came with a 10 Oz bottle of nitromethane! After using a few ounces in my 2.8 1983 Ranger now & then, a few years later the cat became plugged. But she did run like a scalded hog! Just moaned up the hills on the 101 hwy. The mechanic said when a loose rag failed to be blown out of the tailpipe, he knew it had to be a plugged Cat, "better than a potato" I said.

Any place that makes you wait for 3 hours to register a vehicle (California) can go suck an egg as far as I am concerned. Do miss the geology in that state. I was in the emission monitoring instrument business for a few years, My company made a catalytic converter (plug) for natural gas fired turbines that basically emitted no NOx, and very little CO. Only mainly CO2 & water. The best resource for energy in my opinion. No waste & everything is rebuildable.

 

[19Walt93]

Have you considered having a dealer diag the problem? The guys who wouldn't work on it because someone else had been there before are just afraid they'll mis diag it, too. A dealer's labor rate might be higher but the techs are apt to have experience and training.

 

[85_Ranger4x4]

Have you considered having a dealer diag the problem? The guys who wouldn't work on it because someone else had been there before are just afraid they'll mis diag it, too. A dealer's labor rate might be higher but the techs are apt to have experience and training.

On a '03... anyone's guess. It could very well be older than the tech wherever you take it.

 

[19Walt93]

On a '03... anyone's guess. It could very well be older than the tech wherever you take it.

Even a young tech can read the manual online.