Tuning Fiat punto mk2 decat manifold

[BTG]

Hi all ,

thinking of buyin another fiat punto mk2 manifold and cutting the cat off and welding a pipe in place to act as a decat

but on my punto im sure it has 2 lamba sensors one reading in and one reading out

ive heard of lamber sensors blockers and people unsing tinfoil

im sure one person has done this on here just wanted to know how they have blocked the sensors

any help and pics would be great

Thanks
BTG

 

[DaveMcT]

Decat pipes make cars stink**. A far better option is a tubular manifold and a sports cat under the floor.

** All except HGTs which have precats which can happily be junked but the O2 sensors must be retained and connected. Precats allegedly improve startup emissions but when its all heated up they cost power and fuel economy. IMHO lose more than they gain % and better got rid of.

 

[mbonner02]

all i done to mine was cut the under cat pipe off, drilled through the cat then shook it out and kept breaking it up with a pry bar and shaking it all out. blastged it through with air then put it back in the car in the 2 separate parts, tacked them together, took it off and welded it properly

 

[s and b]

remember new mot rules in january will cause a fail for any car that has been decatted that came factory fitted

 

[DaveMcT]

Precats wont affect the hot emissions test done by the MOT and a deprecat done carefully wont be obvious from the outside. Just bashing out the internals will probably do next to nothing for the gas flow as the gas expands into the space then has to squeeze back down into the outlet pipe end result turbulence and poor flow.

Apart from that running a catalysed engine without a catalyst is about as irresponsible and selfish as it gets. All the excess fuel that should be burnt in the cat to clean up the emissions is now pumped out the tail pipe along with all the crap it was supposed to clean out. Best of all the car will probably be no better performing and quite possibly worse as all the back pressures will be wrong.