Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Leonwhite on 17 July 2019, 20:30:35

Title: Omega de cat
Post by: Leonwhite on 17 July 2019, 20:30:35

Hello was just wondering is it ok to de cat a v6 omega will it throw up and any engine lights or is there any sensors to worry about

Title: Re: Omega de cat
Post by: Doctor Gollum on 17 July 2019, 21:15:14

I would be more concerned about it passing inspection without...

But to answer your question, yes it will put the EML on and it won't run right as the ECU needs the O2 sensors to regulate fuelling. You might get away with it if you fit the sensors to the decatted pipe but the emissions will still be off.

Title: Re: Omega de cat
Post by: Leonwhite on 17 July 2019, 21:29:40

Thanks it is for a track car so not worried about inspection so u think put the sensors in the de cat pipe may work

Title: Re: Omega de cat
Post by: TheBoy on 18 July 2019, 09:49:52

Which V6?

Title: Re: Omega de cat
Post by: Leonwhite on 18 July 2019, 15:39:00

2.6

Title: Re: Omega de cat
Post by: Jan Suhr on 18 July 2019, 17:25:19

You need both sensors and the one that is after the cat will throw error codes.

I don't know if it is possible to cancel the 2nd sensors from the ECU with a TechII, but if it is you need to do that to not give the errors.

Title: Re: Omega de cat
Post by: Enceladus on 19 July 2019, 16:19:32

If the O2 sensors are throwing errors doesn't the ECU limit the engine to 4k rpm? Not desirable on a track car.

On the 2.6/3.2 each bank has a pre-cat and a main cat. The downstream O2 sensor is in-between the two, unless it's been modded. Therefore I imagine that you could remove the main cats, leave the pre-cats and the ECU would be unaffected, whatever about actual emmisions measured at the tailpipe?

Title: Re: Omega de cat
Post by: TheBoy on 19 July 2019, 19:04:24

Quote from: Jan Suhr on 18 July 2019, 17:25:19

I don't know if it is possible to cancel the 2nd sensors from the ECU with a TechII

Its not.

Title: Re: Omega de cat
Post by: TheBoy on 19 July 2019, 19:06:47

Quote from: Leonwhite on 18 July 2019, 15:39:00

2.6

So doesn't have to be road legal?  The ECU will not adjust its paramters just because there are 0420 and 0430 codes (cat inefficiency codes).

There are 2 cats per side, a "starting cat", also known as a pre cat, and the main cat.  On the 2.6/3.2 these are cheap nasty things. 

Title: Re: Omega de cat
Post by: Raeturbo on 19 July 2019, 22:34:44

So how can we just do away with the four of the fuuuuing things and still run the car ok then?

Title: Re: Omega de cat
Post by: Kevin Wood on 20 July 2019, 10:14:29

Quote from: Raeturbo on 19 July 2019, 22:34:44

So how can we just do away with the four of the fuuuuing things and still run the car ok then?

No, it needs the front sensors for closed loop mixture control.

If de-catting, best bet is to fit the sensors to the new pipe and ignore the P0420 / P0430 codes.

Title: Re: Omega de cat
Post by: Raeturbo on 20 July 2019, 10:20:08

Thanks👍