diy 172 decat (pikey post #2)

[Rob Clark]

ok lots of current discussion regarding Ik and decats atm and am sortof considering both (prob itg panel for now).
Thing is with decat, whats the overall crack ? Am guessing removal reduces pressure on the exhaust which produces positive results for the effeciency of the engine (ableit with a frown from the environment agency)
So is it just a case of matching the inner diameter of both inlet and outlet (im assuming theyre the same ?) & matching the flanges (ditto).

I say this as im considering getting a m8 to play and weld me one up. Looking at asking dealer if i can keep my faulty one im getting replaced under warranty and matching its length, etc.
Only question is if the 2nd sensor needs a place to be house or if it should be taped up and secured out of system as it woill always show out of spec readings with no cat

to be used with group n ecu btw (aka pikey project #1)

 

[edde]

ok lots of current discussion regarding Ik and decats atm and am sortof considering both (prob itg panel for now).
Thing is with decat, whats the overall crack ? Am guessing removal reduces pressure on the exhaust which produces positive results for the effeciency of the engine (ableit with a frown from the environment agency)
So is it just a case of matching the inner diameter of both inlet and outlet (im assuming theyre the same ?) & matching the flanges (ditto).

I say this as im considering getting a m8 to play and weld me one up. Looking at asking dealer if i can keep my faulty one im getting replaced under warranty and matching its length, etc.
Only question is if the 2nd sensor needs a place to be house or if it should be taped up and secured out of system as it woill always show out of spec readings with no cat

Just get a second hand cat then mesure its lenght and cut the cat bit oof and weld n a pipe in place of the cat.
Renault dealers won't let you keep the old cat as they need to send it to Renault so they get pain (renault should ask for it back to find out why its failed)
The second sensor so long as its not pluged it won't case any trouble. if you need to use the sensor itself to block a hole fine just take the wiring for it up out of the way so it won't get dirty etc.

 

[16v_jon]

I had a jordi special de-cat fitted, cut the cat out and welded a pipe in its place, chris n nic have also had this amazing decat!
regarding the second 02 sensor leave it plugged in the light will come on but the car will perform no different, if you unplug it the car will run like s**t. your into your electronics why not design a device which sends a fake signal to the ecu?

 

[Rob Clark]

depends on which route i go down, butchering a standard knacked cat or making own as was reffering to if a made up decat should have a housing for the sensore.

re: fake signal im guessing that the original one works on a resistance basis so if a known good resistance is known (shouldnt be hard) simply replacing the sensor with a fixed resistance would work, ill see what dialogys throws up later.
Step #2 is to chat to local dealer mech to see when he next has a 172 cat replacement due