The Rover-Landers of BC

Hi all, I have a disco 1 1995MY with the GEMS 3.9l V8. It has a rattly cat and I was wondering if anyone knows whether these can be run straight pipe without any major issues or triggering any warning lights.
Cheers
Dave

The 1995 Discovery I am using had a cat on the passengers side and straight pipe on the drivers, seemed to work, but seems silly to build that way.

Thats the same set up im running. Bit odd i agree as its then only treating half of the exhaust gasses shirley???

Are you using the exhaust for your series build or are you going custom?

Cheers
Dave

So from the research I've done, everything points towards going straight pipe will not throw any codes as on this particular system (3.9L GEMS) the O2 sensors are pre-cat and not downstream of the cat...

I guess there's only one way to find out but if anyone has any experience with this type of mod please chime in!

Cheers

Dave

From my experience on non rover efi's, if there are no o2 sensors downstream of the cat's, the computer doesn't know that you've removed them.

It's not GEMS, but my 88 RRC is running a later model 3.9. At some point during the transition from the 3.5 to the 3.9 I performed a catectomy. There were 3 blocking up the exhaust so it breaths a lot easier. No error conditions in the 13CU managing the EFI resulted from the loss of the cats.

Cheers guys!

"Catectomy" - Love it!