Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: p.beckwith on 23 July 2010, 23:23:38

Title: sensors on the exhaust system
Post by: p.beckwith on 23 July 2010, 23:23:38

im haveing my exhaust changed next week  by a  friend      where are the sensors on the system    before or after       ( rear of ) the cats ?????????   


yours   faithfully    paul      (got bits from enternal germany)

Title: Re: sensors on the exhaust system
Post by: TheBoy on 24 July 2010, 10:07:17

If you are not changing cats (doubt you are), the sensors do not need to be disturbed :y

Title: Re: sensors on the exhaust system
Post by: p.beckwith on 24 July 2010, 10:19:34

thanks  mr boy

  no not changing cats  just beyond that    2 x  central boxes and rear box    thanks  for info 


  yours  faithfully     paul

( got the 3 boxes and fix kit delivered for £137 )

,.

Title: Re: sensors on the exhaust system
Post by: TheBoy on 24 July 2010, 10:38:04

Yup, nice and easy :y

Eternal do not always supply the correct suitable U clamps, so check before starting.  Also, you will need new bolts for the cat/middle section join.  Probably have to drill the old ones out as well.

Get some exhaust paste for the cat/middle section join and middle/back joins as well...

Title: Re: sensors on the exhaust system
Post by: Enceladus on 24 July 2010, 11:56:05

As I recall the centre boxes to cat bolts are (fine metric?) stainless steel, two per side and not available in the likes of B&Q. I would replace with new stainless or else they will all shear off next you want to separate them ;).

If any of the the bolts shear off you will need hardened drill bits to drill out. (The bolts screw into theaded holes on the cat side.)

I damaged the threads on one of mine, so I  I used a longer stainless steel bolt with a stainless locknut and washer and it's been fine.

Stainless bolts can be had from a Vaux dealer, engineering supplier or marine chandlers. Or the internet.

Title: Re: sensors on the exhaust system
Post by: Andy H on 24 July 2010, 12:23:53

I don't think Vauxhall will sell you stainless bolts. I think the standard fit are run-of-the-mill 8.8 high tensile with standard 8x1.25mm metric threads (not metric fine) and slightly smaller heads than normal for 8mm.

I soaked mine with WD40 (I couldn't find the penetrating oil :-[) every evening for 3 days before changing mine and managed to unscrew 3 out 4.

I wouldn't use any bolts bought from any DIY shed on my car. Chances are that something they sell as 8mm is actually 5/16 UNC and manufactured from recycled baked bean cans.  >:(

Title: Re: sensors on the exhaust system
Post by: Enceladus on 24 July 2010, 22:51:45

For the record;

I still have an original bolt still in bag, I bought four new ones from Vauxhall at the time and only used three. I remember noticing the lack of corrosion on the originals. The unused one is dull grey.

The are M8x35. The hex head is deeper than standard at 7mm versus 5.25 or so. Standard 13mm across the flats.

The bag it came in is marked GM #24434133 and the cat number is 8 55 967, Made in Germany.

The head has makers mark KX2 and the grade is A.

Mine snapped off inside the threaded part of the cat and I also remember rooting aroung in the darkest depths of my toolbox for a harder drill-bit.

So some form of stainless steel methinks but not the standard A2. I guess 8.8 would be fine. But the heat and road spray will corrode them. And next time you need to separate the exhaust = £$%><@*.