Catalysers and Lambda sensors

Having put a few mile on the Guzzi and having got used to it, I want to
free the engine up a bit as its highly strangled IMO.

Under the bike there is a sodding great CAT that the headers go into
and then out to the exhausts.

If I remove the CAT get some stainless tubes fabbed up to replace it
and then create a tap for the Lambda sensor to go into, am I going to
run into any problems.

The Lambda is monitoring airflow/ O2/ CO2 etc, but will the removal of
the CAT change this and then make the ECU misread whats actaully going
on?

--
Gavin.

Moto Guzzi California Aquila Nera
GSXR600K1
Twitter: http://twitter.com/gavin_wilby
Blog: http://www.stoof.co.uk

 

Dunno about the Guzzi, but it worked fine on the R1150 - cat off, remus
pipe on, lambda in the new pipe no problem

 

If there's only one lambda, it'll be upstream of the cat, so removal will
make no difference at all.

It simply reads oxygen in the exhaust, adjusting the amount of fuel to
keep the burn as complete as possible so the cat will work.

 

Its actually right in the centre of it, but there is no way of telling
actual gas flow.

End of the day, and in light of Gyps comment, itll be cheap enough to
get a straight through made up, so not much to loose if it doesnt work
or sods the fuelling right up.
--
Gavin.

Moto Guzzi California Aquila Nera
GSXR600K1
Twitter: http://twitter.com/gavin_wilby
Blog: http://www.stoof.co.uk

 

Doesn't it actually result in some overfuelling (to keep the cat happy)? In
pre-cat days engines could run with leaner mixtures.

Tim

 

Yep. Leaner than stochiometry (14.7:1) on cruise gives better economy,
richer on full-beans gives better power. But the cat'll sulk with either,
so 14.7:1 (or near as dammit) at all times, please.

'course, it's a damn sight easier to put up with the small extra
consumption than to remap the entire management to ignore the lambda...