Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: cruisetopoland on 19 November 2009, 12:00:12

Title: Performance/economy difference
Post by: cruisetopoland on 19 November 2009, 12:00:12
Thanks to OOF and some very helpful club members, my 2.2 auto is nearing perfection now...

It has had everything (not enough space to list with only 6000 characters..!) done, apart from valve lifter additive and exhaust manifold gasket being done this Sunday.

The box/ecu updates have been done by VX main dealer and the cat was replaced by a club member, but since this, economy has dropped by 4-5mpg and the car is noticeably slower.
The removed cat was a cheap, one-box aftermarket job which looked almost new but the innards were loose, this was replaced by a good original off a 2002 2.2-the original VX ones have 2 boxes.

When I read through all the "buy a V6 not 4pot" threads on here, I did not get it as mine used to FLY, but now it is quite sluggish and unresponsive-especially on slip roads onto the motorway.  Is this normal for a 2.2, along with 28mpg on a run, now it is back to VX cat spec, or is there something wrong??

I am assuming this is a cat issue, this being that the knackered one offered no resistance compared to the VX one now fitted, plus the new updates have set the gearchanges at a lower rpm?
It used to be very lively but now needs booting just to keep going...
Title: Re: Performance/economy difference
Post by: rustym95 on 19 November 2009, 21:10:15
have you changed the oil, mine allways gose down on mpg then change the oil and its back up again.
Title: Re: Performance/economy difference
Post by: Welung666 on 19 November 2009, 21:15:54
Oil was changed weekend before last along with the filter and coolant flush.
Title: Re: Performance/economy difference
Post by: tunnie on 19 November 2009, 21:37:29
clean the throttle body, if that gets clogged it affects performance quite a bit on the 2.2
Title: Re: Performance/economy difference
Post by: feeutfo on 19 November 2009, 21:52:49
why was the cat changed, and did the problem start at the same time?
Title: Re: Performance/economy difference
Post by: Welung666 on 19 November 2009, 21:57:15
The cat that came off was a cheap aftermarket single cat pipe and the guts of the cat rattle like crazy as they have broken loose.

Throttle body will be done Sunday :y
Title: Re: Performance/economy difference
Post by: cruisetopoland on 20 November 2009, 08:09:50
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The cat that came off was a cheap aftermarket single cat pipe and the guts of the cat rattle like crazy as they have broken loose.

Throttle body will be done Sunday :y

Cheers, that may be it.  The old (newish) cat was shot to pieces-a clear case for avoiding cheap ones.
The whole car has been gone through-many thanks for the help-much appreciated!!
Title: Re: Performance/economy difference
Post by: cruisetopoland on 20 November 2009, 08:12:12
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Oil was changed weekend before last along with the filter and coolant flush.

As well as coolant change/flush and ATF change it's had an engine flush and two short (1500 mile apart) semi-synth changes, both with genuine VX filters.
Title: Re: Performance/economy difference
Post by: Andy H on 20 November 2009, 09:03:27
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why was the cat changed, and did the problem start at the same time?
Did the lambda sensor(s) get swapped with the cat?

Could a duff sensor or an air leak have been introduced?
Title: Re: Performance/economy difference
Post by: cruisetopoland on 20 November 2009, 09:14:04
Quote
Quote
why was the cat changed, and did the problem start at the same time?
Did the lambda sensor(s) get swapped with the cat?

Could a duff sensor or an air leak have been introduced?

We re-used the cars original sensors and they were done up tight, will check on Sunday-cheers  :y