I am replacing the stock catalytic converters with with 200 cell high flow cats from Nameless Performance. Without a doubt the configuaration and design of the stock cats is the most restrictive portion of the exhaust.

Here are photos of the NP cats next to the stock units. You can see how much less restrictive the NP design is. Add the reduced cells/inch count vs. the stock units to also improving the exhaust flow, along the special pricing offered by NP, made this any easy decision as the first performance mod to my car.

The NP units are really well made and fit perfectly in place when I test fit them. I installed some a heat shield where the steering shaft crosses next to the cat to protect the rubber cover.

The stock units are fine with no sign of overheating or clogging. The driver's side cat was a challenge to remove from the exhaust manifold because of the expansion tank, houses and heat shield blocking the bolts.

Does anyone think I should change the 4 oxygen sensors due to age and mileage (87K)?



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2001 VPD S/C

 

That looks very nice. I am hearing some rattling from what sounds like an exhaust/cat issue. Are the NP cats reasonably priced?

 

They were on sale however I think the sale has ended now. Nameless Performance has a posting in the XKR section.

 

I have never noticed any difference in performance from replacing a working O2 sensor -- Some claim greater gas mile but I have never noticed any change.

The driver side upper sensor is a pain to install --- but it sounds like you already put that side back in.

Most of our fleet cars go 200k and we never touch any of the sensors -- although on the ones we have needed to replace it has been the heater in them and not the sensor that failed.

 

Yeldogt- thanks for the feedback on the sensors. The cats must have been installed attached the engine on the assembly line judging on how hard it was to get to the studs from the engine compartment.

1 of the studs is angled towards the head and impossible to get a straight extension on it to break the torque.

 

Removed mine when I installed the new trans, a real pain. The heat shield on the drivers side was the hardest because had to remove water reservoir and hoses under it. The hose clips must have been installed before the motor was in due to the fact that all of them had the clips pointing down and hard to get at. Those are nice units you have there.
Bill

 

Have you been able to replace the lower sensors without removing the cats?
Any tips?

 

Squish, we will be offering a 5% discount for all forum members on our next run of cats (down from our 20% off release run). That puts them at ~$710 a pair, which is far less than half the cost of a single factory catalyst. So yeah, pretty good deal if you have a rattling cat (usually from the expanded vermiculite packing around the ceramic catalyst blowing out from the supercharged high exhaust temps).

I'll post up the discount code soon, but incase you're wondering, it will be JAGFORUMDP.

As for replacing the O2 sensors, I'd just leave them if they work properly. The other thing to consider is some of the discount parts houses make mistakes with O2 sensor part numbering when it relates to the XKR and XJR. I have heard of two owners buying replacement sensors and getting the wrong sensor (secondary I believe).

J

 

An invaluable tool when working around the coolant reservoir is a good set of tubing clamps so you can stop the flow of coolant out of the hoses safely without harming the hoses. That and a good liquid pump for removing all the coolant out of the reservoir.

J

 

I moved the coolant resevior out of the way be first syphoning out the coolent and then removing only the hose underneath. Then I tilted the reservior, with all the small tubes still attached, up on top of the engne and tied it off.

Next I bent up the top of the heat shield to get to the 4 studs. The NP cats are very well made and they bolted right into position without a problem