precat confussion???

HUDDY

just called my local longlife exhaust dealer to get a price on removing my precat!! 20.gif only to be told and im sure u will tell me they are wrong that they cant do this as it will bring on the fault light and cause high usage of fuel, i argued it with them but they refused to accept?

Daz

the precat doesnt make the eml light come on at all...it was just put there to meet euro 4 regs.
Some 2.2s dont even have it from factory,and as far as the fuel consumption goes theres no diff at all to my knowledge,

Also u posted in the wrong section ,which i'm sure one of the mods will sort out l8r

HUDDY

thats exactly what i put to them but they wouldnt have it

Daz

Me and Prob the rest of us on here who have removed the precats will definatly disagree with them m8...

Andy

as above mate, they are wrong and if it were me speaking to them i would have laughed in their face.

the precat is only required for the emissions test when the car is 1st built, after that its not needed and no eml will come on by removing it and mine has passed 2 mot's without it.

Perhaps they thought you were on about the main cat cos that would make the eml light come on as there is 2 sensors for the cat one before and one after the cat.

JohnnyN

I'm a bit confused here too. When Courtenays removed my pre-cat, they removed the sensor in the manifold and replced it with a special box of tricks to fool the ECU into thinking it was still there.

what.. notsure.gif what..

Andy

JohnnyN said:
I'm a bit confused here too. When Courtenays removed my pre-cat, they removed the sensor in the manifold and replced it with a special box of tricks to fool the ECU into thinking it was still there.

what.. notsure.gif what..

no need to fool the ecu into thinking its still there as it won't affect the car by removing it.

i bought a new downpipe for my car a month after buying the car and that came with the precat removed and i've not had any problems with the eml.

Daz

No sensor in my manifold...unless...uve got a manicat...

vocky

I have a 4-2-1 manifold and even that has never produced an eml

the first lambda sensor monitors the fuel mixture, the lambda behind the cat monitors the performance of the main cat.

solorider

astra/zafira 2.2s made after approx mid/late 2002 never had the precat,also sometime after this the egr valve was removed as well,if you bought a new cat from vauxhall it doesnt have a precat as you have to have the later part no

poundy

JohnnyN said:
I'm a bit confused here too. When Courtenays removed my pre-cat, they removed the sensor in the manifold and replced it with a special box of tricks to fool the ECU into thinking it was still there.

what.. notsure.gif what..

yeh they did the same with mine.

HUDDY

NOW IM CONFUSED? LOOKS LIKE ILL HAVE TO TAKE THE DRIVE TO REGALS AND LET THEM DO IT notsure.gif

Gazza

as above there is no need to fool the ecu to tell it's there i had mine removed 2 months ago and have never had any lights come on notsure.gif

solorider

as i said in my post,if you buy a new cat from vauxhall they no longer have the precat in them (astra/zafira ony) so there is no reason the ecu will bring on any lights unless you damage the wiring or the sensor on removing the pre cat

Gazza

solorider said:
as i said in my post,if you buy a new cat from vauxhall they no longer have the precat in them (astra/zafira ony) so there is no reason the ecu will bring on any lights unless you damage the wiring or the sensor on removing the pre cat

yea agree with that 😃

Daz

Bit confused about the sensor in tha manifold bit?...theres only 2 on my exhaust and there b4 and after the main cat..

Andy

dazsri150 said:
Bit confused about the sensor in tha manifold bit?...theres only 2 on my exhaust and there b4 and after the main cat..

yep same here.