Vauxhall Senator 2.6 - dj67blue
I have a 1992 Vauxhall Senator 2.6 Diplomat. and it needs a new exhaust. The system on the car at present splits into 2 pipes after the downpipe and has 2 cats, 2 centre boxes yet only a single back box.

My query is

A, Can I De-cat this car legally? and

B, can i run a bigger bore (same diametre as downpipe) instead of using 2 pipes?

C, Anyone know where in Scotland (preferbly Edinburgh) I can get a new system made to order?
Vauxhall Senator 2.6 - tr7v8
Pre-Aug 1992 yes it can be de-catted. Don't know anywhere in Scotland but it would be with becoming a member of Autobahn stormers & asking there.
Vauxhall Senator 2.6 - nick
Don't forget you'll still have to pass the emissions test at MOT time. The Autobahnstormers should be able to advise on that.
Vauxhall Senator 2.6 - tr7v8
It'll be a pre-cat emission so 3.5% & 1200ppm HC most designs can manage that unless they have a BL or Rover badge on :-)
Vauxhall Senator 2.6 - dj67blue
Thanks for the help.
Found a good site at
Vauxhall Senator 2.6 - bell boy
good posts cant add ,but nice to read sense
Vauxhall Senator 2.6 - Number_Cruncher
I'm not sure if this is described on the sites linked to above, but, going one stage further, you can also revert the engine to open loop operation by earthing terminal 20 of the engine management unit. Practically, this means that the engine management unit will not use the lambda sensors and will instead rely on its own internal maps, which should give better performance and/or economy depending upon the operating point.


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