if the downpipe is all smooth no heatshields it sounds like the downpipe cat is not on the car and if you take the other one off it will fail m.o.t unless you have a good m.o.t tester

 

Cheers Shaun, yeah i see where the sensor is but it also says front cat convertor, mine isnt like that no bulges just a smooth pipe same diameter all the way down. This is why i think its already been removed.
Wayne

 

if no bulges its decatted so you will have no cats if you put the new pipe on

 

Sorry Peter didnt see your post, yeah the mot bloke is ok and i could always put it back on if required.
Do you think im ok to go ahead and put my decat pipe on?
cheers

 

You will probably need it checked over by a mapper or rolling road to make sure it running ok

 

Ok its going on tonight, i will try the car in the morning to see if it throws any engine lights on. There is a rolling road close to me so i will see if i can get it booked in .
One more question, if its fully decatted and mapped to suit, what happens if you need to put the cat on for the mot will it confuse the car again?
Many thanks to you all for your help on this one, what i thought was a 10 min job has been all afternoon and its not even on yet.

 

Has 1st lamda in the headers. Second lamda is in thr second section as pictured. No lamda in the downpipe. The wireing is clipped to the n/s of the gearbox.

 

If you map it m.o.t just put the cat on then go home and put the decat back on just stay off boost on the way home

 

ok just a quick update, fitted the decat section and started her up, no engine managment lights on which i thought was good as it could have been mapped already .
Now the bloke over the road has just told me the scorpion decat has a raised lambda sensor holder which are designed to stop it throwing a warning light.
So i still dont know if its been mapped , only thing is to get it onto a dyno and take it from there.
If it needs remapping what are the normal costs of this ?
cheers

 

the engine management light can still come on mine came on after about 100miles and a ecutek remap is about 600quid

 

You wont get a engine management light by fitting a 2nd cat delete pipe, only the cat in the downpipe is checked by the ECU. It looks like you had been running with a downpipe decat and no management light already so no reason for it to come on now. If it was going to come on it would be after driving around for a while not on startup.

Not sure what your mate means by raised lambda sensor holder, only way to stop a check engine light for catalyst issues is to turn it of in the map, wire in a eliminator circuit on the post cat lambda sensor or run with a active catalyst.

A open source remap is usually about £350

Do you have a boost gauge ? if so you may be able to tell if its been mapped by the boost reading.

 

Ok, cheers for your replies but in regards to the above quote, yes i have a boost gauge what would i need to look for in the boost reading?
cheers

 

In the olden days before mapping was so common you could buy an electronic box that you attached to the lambda wire (electronic CEL fix) which fooled the ECU into thinking there was a cat. The other method was to "space out" the sensor away from the axial exhaust flow and that was meant to fool the ECU.

Both methods were a bit flakey LOL.

Shaun

 

boost higher than 1.2bar would mosty likely indicate a remap. all depends on gauge accuracy etc.

 

How do i measure the boost? i have a boost gauge but thats as far as my knowledge goes,
cheers

 

Watch the boost gauge and see what it reads........pulling hard in 4th would be a good place to start

Shaun

 

where do i rev it to ?

 

 

Am i just being thick again?

 

Drive in 4th gear then when the turbo kicks in see what your boost gauge read upto about 5-6000rpm

 

ok im off to try
cheers

 

I hope theres not much traffic on the road, he will be pushing 100 mph !

 

VF35 should see full boost on WOT at lower RPM than that

Shaun

 

Ok been out, besides i think i need a new clutch as it slipped which it never did before, the reading on my gauge was around 1.2 i think, the gauge only goes to 1.5 anway.
Does it need a remap?
cheers

 

wish i had read this before i went out!!!! its pushed over that speed!!
(on a private road of course)

 

Stock boost is 14.6 PSI or basically 1 bar IIRC. Looks like it's been mapped if it's sitting at 1.2 ....

You will have to check the stock boost as I'm working from memory LOL

Shaun

 

If you guys were in my shoes would you leave it totaly decatted and get a re-map, or put the centre cat back on and just have a run on the dyno to see what its doing?
If i hadnt meesed with it i would never have known the downpipe cat was missing but now im worried about my engine, you guys talk about over boost and spike and i ahve no idea what these are.
cheers

 

If you have a few quid left over I'd get someone like Duncan from Race dynamix to come and look the car over and check the map

Shaun