6 replies to this topic

[Finchman]

Started my 1999 MPI cooper this morning and the tick over was a bit lumpy,the exhaust was popping , after a few minutes there was a sulphur smell,I looked under the car and the catalytic converter was glowing red.Is the cat knackered?

[weef]

Assuming the exhaust system post cat has no obstructions to flow, it may be an over fueling issue or a cylinder not firing causing the unburnt fuel igniting in the cat.

The cat does run hot but not glowing red under normal running, I can only think it's an overfueling issue based on my experience when carrying out a forced regen of a cat, usually diesels, where excess fuel is injected into the engine to burn off contaminents in the cat, thats when they glow red and smell a bit.

Hope this helps.

[Finchman]

Thanks,the car was running fine at the weekend, yesterday I did an oil and filter change,so I'm now wondering if I've accidentally knocked one of the spark plug leads.

[Midas Mk1]

Sounds like the cats blocked to me.

[Tupers]

It’s worth checking your plugs, leads and coil.

I had a similar glowing cat on an early 2000s VW. It turned out to be half the coil pack dyeing and unburnt fuel front two cylinders being dumped into a hot cat.

[68+86auto]

From what's been said, it's likely a plug lead is loose or damaged.

[slidehammer]

You could also check you haven't disturbed the Lambda sensor or it's wiring, when you did the oil change.

If it has happen straight after you doing the oil change, I would think you have knocked a lead or pipe.