Hey fellow Jag-sters!
I got a quick question. Does anyone know if the 2000 4.0 oem catalytic converters are interchangeable with the 3.0 cc's? Reason I'm asking is, I've got a 2000 3.0 S type that needs a cat converter on the passenger side and I found 2 oem cc's for both models but the 3.0 cc's is a $120 more. However they look exactly the same. Plus, I have the JTIS manual and the manual doesn't state that they are different. I'm sure they are internally due to the bigger engine, but size wise (length), it looks like they'll fit. Plus I don't see the harm of using the 4.0's on my 3.0. I could see a problem the other way around...but am I wrong in thinking this?
Does anyone know if they're the same or has anyone interchanged these parts?
Any input is greatly appreciated.
Thanks!
These cars are the shizzle!

 

S.Typer, looking at a jaguar parts listing for your year S-Type, it would appear that the cats are different between the engines, even between the supercharged and non-supercharged models.

As for using a 4.0L cat in place of a 3.0L cat, the only problem I see is that your catalytic converters need to operate above a certain temperature to be efficient (ie, capable of converting CO into CO2 and burning any unburnt fuel). It is possible by running the larger engine cat, you won't be able to maintain the minimum operating temps, which can lead to Check engine lights and whatnot. I wish I could be more specific, but the info isn't available at the moment for me. They may work, they may not. But, at the price of a cat, it is a hell of a gamble.

 

Thanks Thermo. It was specific enough and like you said, it's an expensive gamble, one that I'm not sure I want to take. The thing is, I've had this problem for about a year now (P0420) and I just noticed in the last month that, right under my passenger side cat, a little bit of water leaks. I thought it was my cooling system but I did further investigation and saw driblets coming from right above my cat coverter (and yes my expansion tank did crack and was immediately replaced, thanks again to this forum for the heads up).
Both cats were replaced a few years ago by the previous owner but they had universal ones welded on. I was amazed at the short life, only 1 year. The driver side was going out too (P0430) but doesn't come on as much as the pass. side P0420.
I changed all the O2 sensors with no luck.
I was just concerned that if I continue to drive it will I ruin the engine/exhaust system?
I'm also jaded about using another universal cat since this one only lasted about a year. Unless anyone knows of a GOOD universal cat or a decent priced oem one.

 

S.Typer, running around with a bad cat, as long as it is not blocking the exhaust path, it will be fine. THe "problem" with this is the fact that your emissions are now out of tolerance and if you got to a picky place, they could write you a ticket. But, no cop runs around with an emissions tester in their car. So, as long as the exhaust isn't big black clouds, all should be good. If you exhaust starts to smell like rotten eggs and you are feeling a loss of power, then that is a sign of the converter really failing, which can then lead to engine damage.

As for a good quality aftermarket cat, I think it is more a chance than saying Company X is good, Company Y is bad. So, wish you luck.

 

S.Typer, have you looked at all the O2 sensor waveforms to check they are OK?

You say you have changed the sensors. They're not especially cheap so you obviously would have looked at their waveforms first (cheaper than the sensors). What was wrong with them?

What's the mileage on your car?

Are you 100% certain the new sensors are the right kinds? I ask because using the wrong types would mislead the PCM and maybe those codes would then result.

Remember that a code is often a hint not a diagnosis.

 

-Jagv8
No I don't have an O.scope so I have not looked at the waveforms. The two sensors I bought were Bosch, $80+ for both.
My mileage is 129k.
I've been recently looking into other possible causes suck as leaks. I'm going to check all these out first before I embark on buying new cats. IMT seals, breather elbows, thorough check of all thee airlines and suck. Then I'll go get a leak check, if there is none and I continue to throw code, I'll put my old o2 sensors back in, drie around for awhile and see if it throws code. If it does, I'll break down and get some new cats. My emissions test is coming up soon so I'd like to have these all checked out first.

 

It would be interesting to know what the emissions tests show without the P0420 fixed... I wonder just how sensitive those Catalyst Monitor Sensors really are.

(P.S. I am having similar problems. If I find the $300 5yr warranty direct-fit Cats I found earlier again, I will let you know.)

 

You don't need a scope to look at the waveforms, although it would help!

 

BTW: Both rear sensors and the Catalytic Converters have a nice little oval symbol stamped on them with some word in the middle that starts with an F.... ord?!?!!?

Yes, they are stamped with that famous original American-made automobile emblem! So I am guessing they are original. Like the 3.0L engine must be purchased from a European Ford plant or supplier. All but one of the ignition coils were Motorcraft and all spark plugs were as well. I did not read the fuel injectors when I had them out... but!

(Also the lower intake O-ring (not quite O's) are the same for the '02 Lincoln LS and the '02 Jag 3.0L engines. But the upper gaskets are NOT THE SAME! No place local could get the uppers. Everyone had them for the LS in a hard plastic 'support' and they will not work in the 3.0L Jag manifold. You need the 6 free O-rings (these are oval) for the top, between the plenum and the lower manifold. I guess I need to write this part up one of these days with the pics I took. But I'm tried tonight.)

 

But beware: The LS Cats I have seen have three bolts at the manifold and three ports for sensors... So make certain if you get the LS Cats you get ones with two manifold bolts and two sensor ports.

I sure wish I could find the company that has the LS Cats that said they would pay return shipping and give a full refund IF they did not fit the same year S-type! (Where is the knocking head emoticon???) They were direct fit with three bolts to loosen to change them out! All for $300 each including shipping...

 

I've been researching like crazy on the cats. I did notice that some of the LS cats do have 3 o2 sensor ports. But some do have 2.

Whats funny is that I found a couple of sites that sell the 4.0 s-type cats and say its interchangeable with the LS 3.9's and the 3.0 s-type's with the 3.0 LS cats. But when I search for just the LS cats, not only is it cheaper but the cat's don't look nothing alike. The entire pipe w/ the cat looks the same though but the cat's themselves don't.

Reason is, I was looking for universal cats because I think it would definitely be cheaper just to cut it off and weld the universal one in (a certified jag tech on this forum said it would be too) and I found universal ones for the LS, but none for the Jag.... well at least it doesn't specify that it's for the s-type.
So if anyone has put a universal cat, such as a magnaflow or even a catco or davico one, how is your car performing?

As far as the intake manifold gaskets, both upper and lower have 2 sets of 3 holes right? I'm aware of the oval ones for the upper and the oval with that half a circle sticking out of it looking ones for the lower manifolds, but did you replace the lower breather elbow while you were down there as well as the IMT seals?

I found a site with the breather elbow, upper breather hose (the one with the T that splits out of the intake tube and into both sides of the valve covers), and upper and lower intake manifold gaskets that sells these parts for cheap. The IMT seals though you need to get from the dealer.

-JagV8, as far as the waveform goes, is it because the o2 sensors just switches on and off? That would explain why no need for a scope. A multimeter would be enough.

 

Be aware that it may be an offense to fit a cat along the lines you mention
Many countries now require by law that only cats specifically approved for the particular vehicle be used.

The O2's switch too fast for a multimeter to pick up sensibly (but if you got, say 0V then you've a clear problem). Easy to see with scope or OBD, however.

 

Well hey, I have a OBD scanner, if I post up the freeze frame data you think you could help me decipher it? I wouldn't know what the "good" value ranges are.
Also, I wasn't trying to do nothing illegal as far as the cats go. I have to pass emissions coming up so everything has to be legit. I just don't want to spend an arm and a leg buying 2 new cats. I was wondering what kind of universals ones, if any, I could use and if anyone has used any if they could point me in the right direction. I can't remember what jag tech told me that it was cheaper to go that route. However, he was from Canada and I'm in the US so our emissions laws might be different, I don't really know.

 

I'm willing to have a go with the freeze frame data. It won't show O2 waveforms (which need several data points - as you'd expect to be able to see the shape on a graph).

The laws may not apply where you are and anyway they seem weird since all anyone wants is to pass emissions! It kinda smacks of restricting owners to the more expensive cats n that sounds anti-competition. Really weird. I would hope you can still buy cats far cheaper than from certain places.

If your scanner can record and/or graph data, have a play with it and you'll probably figure out how to look at the O2s. They're likely to be called something like B1S1 (bank1 sensor1) or HO2S1 and so on. Volts are the usual things to graph but the upstream ones are wide-band (aka linear) sensors and I don't know much about those. The downstream ones should have a smallish signal (like 0.2V I think, but not zero which would mean broken) and not move around much (the cat's supposed to have done its work).

 

Here's the data from my OBDII scanner. Please tell me what you think.
Thanks

2000 Jaguar S-Type 3.0
DIAGNOSTIC TROUBLE CODES
Code Definition
P0430 Catalyst System Efficiency Below Threshold (Bank 2)
P0420 Catalyst System Efficiency Below Threshold (Bank 1)

MONITOR STATUS
Monitor Status
MIL ON
MisFire Monitor Complete
Fuel System Monitor Complete
Comprehensive Component Monitor Complete
Catalyst Monitor Complete
Heated Catalyst Monitor Not Supported
Evaporative System Monitor Not Complete
Secondary Air System Monitor Not Supported
A/C System Refrigerant Monitor Not Supported
Oxygen Sensor Monitor Complete
Oxygen Sensor Heater Monitor Complete
EGR System Monitor Not Complete

FREEZE FRAME DATA
PID Description Unit Value
DTC for which Freeze Frame was Stored P0420
Fuel System 1 Status Closed Loop
Fuel System 2 Status Not Supported
Calculated LOAD Value 60.39%
Engine Coolant Temp 204.80 F
Short Term Fuel Trim - Bank 1 -1.56%
Long Term Fuel Trim - Bank 1 2.34%
Short Term Fuel Trim - Bank 2 -5.47%
Long Term Fuel Trim - Bank 2 7.03%
Fuel Rail Pressure 39.57 psi
Engine RPM 1822 rpm
Vehicle Speed Sensor 21.13 mph

 

Thanks for posting those. Before I forget, did you figure out if your scanner can graph the O2s? (Post the scanner name and model details if need be and I'll try to find it on the net.)

I'm not an expert on jags, so if any Tech is willing to join in that would be great.

Also, I know the V8 more than the V6 but let me kinda think aloud.

The monitors are complete, which is good - except the EGR! Not good. Don't forget that, as it is a clue. (Possibly one to chase, possibly one to ignore for now.)

The Fuel system 2 status has me worried. I was expecting (hoping) it to be closed loop. Or possibly open loop or even fault.

Anyone else with a V6 (preferably before the facelift) know if it ought to be other than Not supported?

Bank 1 closed loop means nothing grossly wrong has been seen by the PCM (and indeed that sensors look plausible). It's looking at MAF (air flow), and especially the upstream O2 sensor. However, there could be a problem that the PCM can't detect such as a lazy (old!) O2 sensor or misreading (usually dirty) MAF - which is why I mentioned "grossly".

The bank 1 fuel trims are good - you basically look for Long term not many % and then add both trims and again hope for a low %.

Bank 2 are not bad but are different. The Long term shows the PCM is adding extra fuel, so you may (or may not!) have an air (=vacuum) leak. The V6 is known for such leaks - have you replaced any of the usual pipe elbows? (You may need to do some searching or someone may be helpful and post the links - but check posts by BugDoc)

I'm a bit puzzled by the large Load value. I'd have to guess you were speeding up rapidly.

About the EGR monitor. Have you cleared the codes (DTCs) recently or disconnected the battery? Roughly how long (time) / distance ago if so?

BTW, The water drips could be from the a/c.

 

Oh - you changed the O2s. So long as you definitely used proper equivalents and got the wiring right, they should be OK (but the waveforms are the things to look at).

 

I think some of the earlier cars (maybe yours) don't have EGR. If yours doesn't, OBD should report it as Not Supported.

 

My '02 3.0L has 2 sensor ports... One at the front of the Cat and one mid-way through.

Yup. A couple of months ago I called one of those companies that had cheap Cats for the LS and they said they would give a full refund and pay shipping if they did not fit. Just make certain you talk with them and get the correct one.

Unfortunately, my wife 'cleaned' and threw away my notes...

I have not done it. It could be done I am certain. You could probably even oversize, but find a good place that will give a warranty against rust. Those welds tend to not last if they do them wrong.

By "breather elbow" I assume you mean the one that goes on the pcv valve. I did not replaced it. It looked new. But the pcv valve, I replaced and it is availbable through Autozone and the same as the LS.

I replaced the upper T-valve (above the driver's side bank of coils and plugs) with a brass T junction. It was also avalable locally.

I would REALLY like to see a new thread started on reading the O2 sensor waveforms including pictures of the equipment needed and how to interpret them. JagV8, can you help us with that? It would be a BIG help to many on this forum! Thx.

 

I'll have a go but probably need to put files somewhere - could be csv or xls and maybe jpg - can I do that here?

It will take me a while cos the software to read OBD is for Windows but I use Linux so it's a pain (and besides I'll have to write stuff up)

I'll only be able to do my car - an STR - but the ideas should be the same for any petrol model