have swapped o2 sensors and coils still codes to 1,3,5,7, misfire along with random misfire and occasional cat below threshold efficiency. replaced fuel filter.
ltft bank 2 is 3-4% high than bank1 and when driving they go at 5 and say 8 or 9 % positive respectively . the o2 sensors on the left from inside bank were sooty and the right from inside were grayish.
i have camera inspected and backpressure inspected the cats seem good i can see the matrix grid intact. the left bank it seems is a replacement non jag branded the right is jag. the kitty has 100k mile on the odometer.
i am leaning toward a vac leak at this point? could a boost leak set these codes off?

 

may try swapping mass airflow side to side ? out of ideas before throwing parts at it. fuel pressure seemed adequate only dropping off after the restricted output warning comes up.

 

You swapped the coils on a supercharged 4.2? That's a crap-ton of work.
It sounds like a vacuum leak, but not likely on only one side because of how the intake works.
I'd more lean towards something fuel related, but only on that one side is also a bit weird. Maybe something do to with a stuck-OPEN injector? That happens on the five liters with GDI sometimes. Never heard of it on a port injected engine though.

 

Also, just to rule some things out, have you tried a Hard Reset yet? The easiest way is to disconnect the battery completely overnight. It's quicker to touch the detached cables together, but some people get leery about doing that.

 

you stated your bank 1 cat is aftermarket junk…look no further

a bad boost leak will cause cause a p0236 and fuel cut

 

Swaping coils took half an hour.

 

I came to me with bank 1 and 2 cat below threshold efficiency.

 

Hard reset. Will try that. Have reset codes multiple times
p0236 not a set code.

 

@xalty may be on the right track…. only one of the cats replaced? and with aftermarket crap. Not what I would have done.

 

Put a spacer on my O2 sensor and same codes came up and to remove spacer then I replaced cat to get rid of PO430 code.

 

In one of your posts you mentioned BOOST, so I assumed you had an /R. Yeah, non-supercharged 4.2 engines are super simple to access coils and such.

 

I took my 420 cat out and flushed it with all sorts of stuff the Interwebz recommended. It flowed well from jump though. Put it back, same codes. It was emissions inspection time so I put a spacer on, codes have not come back and it's been several months now.

 

learning as i go with this. misfire 1 3 5 7 are bank 1. aftermarket cat is on bank 2.
sealed of the large line to the throttle body as it was suspicious .
replaced the pasta brittle line going to the fuel pressure regulator and omitted the 3 way fitting and the blocked of one way valve (i assume its a vac test port)

 

 

The brittle hose was a vacuum line not fuel. Seems jag/rover use the worst plastic rubber on the planet. Put new sparkplugs in today. Try after roads dry out. Why are these monitored so well but can't tell you whats actually wrong?

 

So i replaced the fuel pump because it was suspect. No relief.
set a code for misfire on 5 but scanner shows no misfire on 5 but 3 is busy misfiring?

 

Is this the the vacuum line to the brake servo?
There is also a seal connector which plugs into the throttle body and the plastic pipe (brake booster) goes into. The O ring seal could still be leaking even with the plastic pipe plugged.
You need to get this tight, and stop drawing in air. Then see what codes are left.

Looks like this.https://britcar.com/product.php/2868...__xf_2009_2010

iT is not quoted for the STR 07, but it is there in the throttle body, so would expect you (XKR) to have the same. May cure part of your problem.

 

Did yet anothe smoke test. Large hose from hockeypuck was seeping. Fixxed that.
egr solenoid seems to let some smoke out. Is that portion serviceable? Or would i need to replace the whole valve?
havent driven it yet but now cyl 2 is actively misfiring. I shot all the coil connections with deoxit.
any opinions on swapping maf left to right?
will post stft and ltft after its together yet again

 

Still wonky showing live data cyl 2 misfiring. Codes state cylinder 3 and misfire on startup.
ordered a rail pressure sensor roll the dice hope for a miracle. Going to do compression test and try leakdown tomorrow.

 

Just so we are all on the same page regarding cylinder numbering!