Hello everyone, 2010 XKR 5l, I have found lately that when my engine is hot (this maybe after 100 miles of travel) during motorway speeds, the car almost stalls when using the kick down. If I then back off the throttle and gently increase on the accelerator it does pick up. When this fault occurs I generally get a limited performance warning, so obviously I back off and trundle along sedately. Eventually the limited performance warning disappears and I continue on my way. I appreciate this could be a multitude of causes, and I don’t have a code reader to investigate myself. So using the limitless wealth of knowledge here, I thought I would start with this post. Where would you guys start with this issue? Should I invest in a good code reader? I would appreciate any thoughts on this, thank you in advance.

 

clogged cats?? need to see the codes to confirm.

 

Clogged cats? Would that be my catalytic converter’s (excuse my ignorance) and I appreciate it’s a guess without the necessary codes, but is that something I could get checked, or easily looked at?

 

How does it perform if you pull the downshift paddle a few times as you mash the skinny pedal?

Sounds like an electrical problem to me, maybe you should check the battery for at-rest 12.6 volts and probably do a hard reset. All may be well afterwards. Maybe not, I don't know. It's where I would start looking.

 

Yes. The catalytic converters are often overlooked…. and the root cause for such situations until its too late.
Also, as @Cee Jay suggests… but we still need the codes.

 

I appreciate all the responses, I did a quick google on Catalytic converter cleaning and that seems like a waste of time (unless you guys no better) and it would seem replacement would be the only cure, should this be the case. I know the codes are king for any issue, I don’t want the post to go off at a tangent but what reader would you recommend? If I’m going to invest in such a device I would prefer one that can do all sorts of codes, like media, abs etc. Again your advice is gratefully received 👍

 

I took one of my cats out because a Fault Code and used several different cleaning methods; soapy water, solvent, and distilled water with either vinegar or ammonia (can't remember which). None did any good, but the flow was still very good as all the honeycomb was perfectly clear. Guess the media just deteriorated. I cheated by using a spacer on the aft sensor and all works fine.

Now, my SON'S XKR also had a bad cat, but his was in pieces blocking flow. He's broke so we got him a cheapo Rock Auto cat for $300. It fit like crap and was much smaller, but it works. I still have the original one, and those can be rebuilt for $400 or so, each.