error code 44 help

[muaythaikid]

Alrite well i was driving down the motorway a few months ago at about 80 - 90 mph and the CEL came on i reduced speed to bout 60 and it went away so i pressumed it was nothing iv recently changed my standard backbox for an aftermarket one and when i was on the motorway the light came on again so when i got home i did the paper clip trick and came up with code 44 anybody able to help me with this i know the code means o2 sensor to lean but what exactly does that mean

When i changed the backbox the gasket was grinded off and now for the moment there is no gasket between backbox and is blowing from that area would that cause the code also would that make a big loss in power car doesnt seem to wanna go faster than 80 mph even down hill it struggles

Theres also a ticking noise when accelerating and i think it might be a bad manifold gasket would this be accurate assumption and could this cause the error?

On another note will 256mm brake discs from 1.6 lanos fit my 1.4 and will i need 1.6 pads etc

Thanks for any help

[benzino]

A gasket leak before the o2 sensor will cause it to code as the comp will think it's running leaner than it is.

Any 256mm brake setup will fit, you will need the callipers and pads to match as well. You can use them from the 1.6 lanos or the astra mk2 and mk3 or a 4 stud calibra... You can even use the lmf bbk or the k-sport bbk but that's probably overkill for your application

[muaythaikid]

Thanks benzino but if it was the gasket wouldnt the error code be on all the time not up around 80mph any idea why the car struggles to go faster than 80mph?