Catalyst glowing red

Hi all,

First Happy new year, hope it better than the last one…

I have not used my 91 XJR-S much last year, as I was working on other projects. I have started her up regularly, and she fires straight up ok. I noticed this time the CAT on the driver side LHD was stating to glow RED. I immediately shut down the engine.

Looking through the past posts, it seems if the rev counter is night working its a problem with the IGN. Rev Counter is ok.

1, this is a 6L pre-face lift with Zytek Ign. possibly one cyn not running and dumping fuel into the cat

2, It seem likely the cat is Toast, (its 30 years old) and looking around the Jag Sport Cat seems to be no longer available. I was thinking of removing the innards and running without the CAT, any thoughts on that?

3, I will change the car to Vechule collection (in France) this year as its 30 years old, which means it has less stringent emission requirements and only needs to be tested every 5 years.

Thanks in advance


Were these posts specific to the XJR-S? Although it shares a (gutted) distributor with the Lucas cars, the ignition system is quite different to other V12 cars.

After a visual inspection of the ignition leads and injector harness on that bank I would pull the plugs and see if one is visibly different to the rest.

Although the cat is toast, its good news that you caught it before very bad things happened.