I have an 07 XKR. I developed a progressively worsening p0300 and p0316 and codes for misfires on 2, 4, 6, and occasionally 8 over a 3 day period. I limped home the last 1/4 mile at sbout 5mph at idle. I had replaced all plugs about 3 months and 2k miles prior so I was in there with all the brittle plastics etc. I did gap plugs and torqued. Battery is new and holds 12.8 at rest. I've switched coils from one side to the other. I changed oil and verified VVT volts and ohms. I checked electrical specs on O2 sensors and upstream was a bit suspect so I replaced all 4 (just cuz). I had received a p0430 5000 miles or more back and it would rarely show and I could clear it with Torque Pro. It did go away after plugs...??? I've hooked up JLR SDD v136 and get wildly fluctuating fuel trims on bank 2. I pulled air filter and it was 'normal' dirty and replaced. While there cleaned MAF sensor. I know that it's gotta be ignition, air or fuel. Absolutely no codes from Bank 1. While I was doing O2 sensors I did the bang test on the cats and the drivers sound more dull thud then drivers. O2 sensors now read pretty good, consistent voltages, but I can't really get (or dare) to run long enough to be sure alls cool. I am suspecting CAT or a vacuum leak on some bank2 specific vac line. Anybody got any advice?

Thanks so much in advance.

 

A smoke test would clear up any vacuum issues.

 

Not sure if wire harness on the 4.2 is similar to 4.0, but in my previous 4.0 the connector of bank 2 injectors into the other side wire harness (at front of bank 2 cam cover I believe) had the moist seal missing and developed similar problems as a result.

Its a while ago do hope I am right and not confused with coil harness, but checking that would make sense too I guess.

Hope this helps.

 

Just to open the discussion, I am not sure if the idea has legs, but to have the OHC off in its timing of that bank, would the timing chain need to be stretched a little, or a guide has a partial failure? As I said , this is to open the discussion of the possibility.

 

I've gotten no cam or crank position error codes but don't know if I would. Some codes these things throw are here today gone tomorrow never to be seen again. I'm gonna check SDD stored codes and see if there were any correlating codes before I bought it.

 

did you do anything with injectors?

this sounds like stuck injector causing entire bank 2 to go down.

 

That's usually the problem with the GDI 5.0 like we have, not so much on the port injected 4.2. I'm not saying NO to that possibility, just way more likely on the 5.0.

 

Nothing done with injectors or fuel rail - maybe some incidental wire bumping..

 

I meant this connector:

 

Checked it and cleaned with electronics cleaner then add some dielectric grease. It was a good connector still with red catch lock, whereas I found 2 others in area that cleaned and had to zip tie to hold 'em. Someone before me was messing up in the front - maybe hoses or water pump....

 

I got underneath with my Klien Tools IR gun to check pre and post cat temps:

There was no load on the engine, idling for approx 15 mins while on ramps. I stayed under for a few minutes and took temps a few times but never got 400° min to activate catalyst. Does this mean they're shot??

Txs

 

Probably at least the one is shot.
Neither are up to temperature though, maybe you should let it run for awhile and take more readings.

 

CATS came in today. From Rock Auto, brand Davico. Removal of old was a little challenging as expected. BP Blaster overnight helped - love that stuff! New ones went on easy. I did run it for a couple minutes straight from the manifold just for the sound, made me smile but p*ssed off a neighbor. Buttoned everything up, cleared codes from straight piping. Started and ran perfectly smooth. NO CODES! Washed it and did a 40 mile top down cruise. All good! The Davico cats are a smaller diameter and they added a really nice rap to sound (fuse 19's been pulled since day 2). Pleasently surprised.

Thank you all for your help.

 

I got a Rock Auto cat for my kid's '07 XKR. It didn't fit without some extended massaging. Certainly not worth the $300 they cost. A rebuilt OEM cat is the same price. Well, at least it works, and I still have the old one to get fixed eventually.

 

Mine bolted right in. Wonder if they sent the wrong side??

 

Mine was just built really poorly. The outlet crimp was too small and wouldn't insert into the center section far enough and the weld holding the manifold flange was too large which prevented the collar from getting out of the way far enough to insert the flange to the downpipe. Just poor QA or manufacturing. Grinding, crimping and welding made it fit 'okay'.

 

"wforslund3" you caught my interest by pulling the #19 fuse for the exhaust! What is the effect, and is it hard on any of the systems?

 

If you have the 'sound enhancement' you can pull fuse 19 and it will make it as though you always have your foot in it. Gives a little better sound. Check your owners manual.....

 

@sony2000 Fuse 19 only applies to the XKR, not the XK (from your postings you appear to have an XK, your car details are not in your profile, and if it’s in your signature, sorry, that doesn’t appear when reading from my phone).

 

Hi Bil,

Your fluctuating Bank 2 fuel trims seem like a significant clue, vbut if they are trending rich, it could simply be due to the oxygen sensor seeing all the unburned fuel from the misfires.

On the other hand, if the fuel trim fluctuations are trending lean but spiking rich, it could be due to an unmetered air leak that affects only Bank 2. I am assuming your car has the supercharged 4.2L engine (it's always helpful to give us engine details since model years vary by country and your car is right at a model change). I don't have a car with the S/C 4.2L here at the moment, but my recollection is that the full-load breather hose and the oil filler neck connect to the Bank 2 camshaft cover. The breather hoses are known to develop cracks, and the O-rings inside the Norma fittings lose their seal. Also, the oil filler cap or neck seals fail. If you see oil around your oil filler cap or neck, air is being inhaled under engine vacuum.

Smoke-testing the S/C 4.2L engine requires connecting the smoke machine at several points. I remove the MAFS and seal its port with duct tape. I disconnect the main air intake pipe from the throttle body, prop the throttle valve open with a plastic trim tool, then reattach the air intake pipe and tighten its clamp. I then inject smoke into the air filter end of the main air intake pipe using a large cone fitting to seal the smoke hose to the pipe. If no leaks are apparent, I disconnect the part-load crankcase breather hose from the and use a small taper fitting to inject smoke into the right (Bank 1) camshaft cover by way of the crankcase vent valve (PCV valve). Then I disconnect the full-load breather hose and inject smoke into the left (Bank 2) camshaft cover. These tests will almost always reveal that one or more of the O-rings on the breather hoses, crankcase vent valve and/or oil filler cap or neck is leaking.

On the normally aspirated engines, the VVT solenoid seals are almost always leaking unless they have been replaced (again, if you see oil getting out, air is getting in under engine vacuum).

Regarding your cat temperatures, we are generally looking for the output temps to be at least 100 degrees Fahrenheit hotter than the inlet temp, but as Cee Jay mentioned, your cats may not have reached full operating temp when you tested them (especially on the passenger side). Note that external temps are usually significantly lower than internal temps due to the rapid heat dissipation of the metal exhaust casing, so it would be rare to measure a temperature as high as 500 or 600 degrees Fahrenheit with an infrared thermometer aimed at the outside of the exhaust.

I'll be following your diagnosis with great interest!

Cheers,

Don