P0300: Random/Multiple Cylinder Misfire
P0301, 303, 307: Cyl 1, 3, 7 misfire
P0420: Catalyst System Efficiency Below Threshold Bank 1
P0430: Catalyst System Efficiency Below Threshold Bank 2
P1313: Misfire rate, Catalyst Damage Bank 1
P1316: Misfire, excess emission

Car runs slightly ragged at idle, stumbles at highway speeds, and has pretty much no guts. If I get on it, I hear the blower really lug, and once it goes above 3k RPM, the RP light goes on. Only did that once.

I bought a full set of coils a little while back, so I just swapped out all the coils on Bank 1 (passenger side US). Made no difference. When I tested it, I thought it was doing better, but then I slowed down to turn around, and the car was clearly having trouble. I didn't check the plug wells for oil (stupid, I know).

What's next? Injectors? Oil down the plug holes? O2 sensor(s)?

What it isn't (because these are new parts, or I've recently solved these problems):

- It's not a vacuum leak. I've smoked the engine, and found all of them and repaired them.
- It's not the fuel pump. Pressure is fine, and never drops below 55psi.
- It's not the fuel rail pressure sensor. This is brand new.
- It's not the crank position sensor. This is brand new.

With all the rich-mixture issues I've been having the past few months, I'm pretty sure the cats are toast.

Thanks,

Ken

 

How's the battery voltage and battery condition?
Condition of the cam sensors?
I think I read on here that the timing chains could also cause a similar problem maybe?
Have you read through the JTIS about multiple mis-fire scenario?

 

Blocked cats can cause misfires.

Or, could be wiring etc to coil(s).

Or of course, bad new coil(s) - especially if aftermarket.

 

This may help you to test the catalyst.
https://m.youtube.com/?gl=DE&hl=de#/watch?v=vyVnhCIMDnw
​​​​​https://m.youtube.com/?gl=DE&hl=de#/watch?v=Cfk8FlgAI6c

 

I'd say your cats are stuffed.

New cats, new O2 sensors, new spark plugs and new air filter. Go shopping.

 

once you've sorted all the possibilities listed above , be sure to check the MAF flow rate via OBD to rule that out to . as the damn thing can cause cat killing richness that in turn causes misfires . like i have had a short while ago . the fact you have misfire & cat codes is the only difference between mine and your symptoms . my cat was toast too but no codes. bad misfiring too but with no codes . still keep it in mind . it will be wort checking to not cook your new cats .

 

Another vote for bad cats.

 

Battery is brand new.
Cam sensors: unknown
Timing chains: probably original

I broke down and took it to the shop. I originally brought it to the dealership, but the service rep there said they had a 2 week wait and suggested a Euro shop not too far away that does good work on Jags. They only have a few day wait, so I left my car with them. It's basically undriveable, and I don't want to risk damaging anything else by driving it around.

 

MAF is good, tested it, and replaced with a brand-new one to no effect.

Thanks

 

Agreed that the cats and O2 sensors are probably going to be replaced.

Plugs are brand new, and I have a Minas intake, so a reusable cone filter

Cheers,

Ken

 

On my way to the shop, it threw codes for the other side of the engine P0302-0308. More evidence of blocked cats? If that's what it is, I'll have to talk to the shop about getting suitable Magnaflow units. Need to find the compatible part number from here on the forums...

 

Magnaflow 2.5" 59956's are what I fitted to mine , none are direct fit , but easy enough to weald in . And weald theaded bosses in for the 02's .
You may have to have your down stream monitors desabled ,
To stop a mil , mine did not need this as its jap spec.

 

Shop called today. They removed the O2 sensors and bore-scoped the cats. They are toast.

So, do I start sharpening up my MIG skills, or find someone to do it for me?

Ken

 

Is there any other reason apart from old age that the cats have failed?
And could you explain the MIG thing please?
Are you thinking of removing the interior and replacing it yourself?

 

This must be at least the 10th case of blocked/choked cats here on the forum in the last couple of years from a 4.2L car.

Age & mileage would have something to do with it for sure.

These cars are 10-15 years old now, I think we will be seeing more & more of these exact same problems in the future. The cats don't last forever.

I have a sneaking suspicion that the cats in my 2009 XKR are also choked up, same like the ones in my XJR were...

 

Are you allowed to use cat bypass pipes over there?
i.e take the cat out completely?
I was able to on my V6 shogun and it had no effect on the mot test, but then it was an earlier year.
I know you can over here, but up to what year I can't remember.
But then I suppose there is the mil light to take into account from the ecu not reading the cat status, and the o2 sensors, and probably more.

Damn they've over complicated cars these days.

 

Oh, I'm just musing on whether I want to try and brush up on my long-disused welding skills, or pay someone competent to do the work

I've found a shop that I think will do what I need without breaking the bank. I ordered in the parts today, so I should be back in business some time next week.

 

No, I'll have to be able to pass emissions testing this year. It's unlikely that, without the cats, I will. Otherwise, I'd bypass them

 

I also have had multiple failures in other components which have caused the car to apparently run rich for around a year. Too much fuel going down into those cats has melted them.

 

From the Day Late/Dollar Short Department, I've heard good things about Davico replacement cats:




2005 JAGUAR S-TYPE 4.2L V8 Supercharged Catalytic Converter | RockAuto




$177 per side, no welding.