would i have busted it?

grant_day · Post by **grant_day** » Thu Dec 15, 2011 6:58 am

So I finally got round to fitting a new manifold and stainless (de-cat) system on my 4th gen, but after all my hard work I've just remembered I forgot to re-connec the O2 sensor (the one that's connected just behind where the cat used to be) , my question is ... Would it have caused any problems for the 50ish mile drive to work and back home???

JayJay · Post by **JayJay** » Thu Dec 15, 2011 9:22 am

The o2 sensor should be fine

It just wouldn't have been sending a signal!

Did you not receive an error light? I would have thought that the engine light would have come on.

Post by **Ammo** » Thu Dec 15, 2011 1:08 pm

Prob cost you more in petrol but no serious damage

JayJay · Post by **JayJay** » Thu Dec 15, 2011 1:08 pm

Ammo wrote:Prob cost you more in petrol but no serious damage

Have you not seen the cost of petrol!

grant_day · Post by **grant_day** » Thu Dec 15, 2011 7:44 pm

If its not going to damage anything ill leave it off, the threads are different sizes anyway so saves a job. Nope no warning lights at all, I thought it was using more fuel but i think its because I was a little lead footed on my way home, before i changed the exhaust I was getting about 320miles to a full tank, that's 520 on the clock, I'm gunna fill her up 2morrow and report back with new figures.

Post by **Kawa** » Thu Dec 15, 2011 8:41 pm

Did you short the wires that used to connect into the cat temperature sensor?

grant_day · Post by **grant_day** » Thu Dec 15, 2011 8:49 pm

Nope, all I did was unscrew the sensor wrap it in a latex glove to keep it clean of dirt etc and tuck it away, then cable tie it out of harms way, block up the hole on decat pipe with bolt l. And left it there. No warning lights or anything

Post by **indigolemon** » Thu Dec 15, 2011 9:29 pm

Ah, this isn't an O2 sensor, I think that's the cat temperature sensor.

grant_day · Post by **grant_day** » Thu Dec 15, 2011 10:15 pm

I see, so no need to plug it back in then? I also read that a bb4 doesn't need a cat for its MOT, due to the fact they can't find an Exact match of chassis number for it, so have to do a non cat test, is this true?

Post by **Merlin** » Fri Dec 16, 2011 10:34 am

If the CAT temp sensor is not plugged in it should give a CAT warning light on the dash. It is best to ground it on the chassis to stop the light from coming on, like so:

If your car is an import and made before 1995 you can get away with a non CAT test. My 1993 BB4 with a Spoon ECU and no CAT, its last emissions test was:

CO2 - Max limit 3.50% - Passed with 1.04%
Hydrocarbons - Max limit 1200ppm - passed with 133ppm