Brand new cat improvements

SB6

I didnt quite know how much a cat does for a car until I replaced the one on my 94 1.4 astra and was surprised so I thought id thow the differences up between 'no cat' and a 'new one' to shows ye too

It went from this with a cat that had literally nothing left in it


To this after installing a lamda sensor, ******ing the timing back to standard and the new cat:


This passes the newer cars 02 onwards regs too, cool
Got it from onlineoutomotive 80 euro all in.....result

Nissan doctor

Just be aware that the very high HC readings on your first test will likely be a symptom of whatever killed the first cat(poor combustion, oil burning etc).

The new cat has masked the HC readings in the short term but whatever the issue is will lead to the new cat failing eventually too.

Mar4ix

Nissan doctor wrote: »

Just be aware that the very high HC readings on your first test will likely be a symptom of whatever killed the first cat(poor combustion, oil burning etc).

The new cat has masked the HC readings in the short term but whatever the issue is will lead to the new cat failing eventually too.

OP mentioned (between pictures) set properly timing belt and changed lambda, so i think both those factors killed old cat. After fixing that, really improved emissions, and i believe MPG too, but that he will notice after a while.

Nissan doctor

Mar4ix wrote: »

OP mentioned (between pictures) set properly timing belt and changed lambda, so i think both those factors killed old cat. After fixing that, really improved emissions, and i believe MPG too, but that he will notice after a while.

So They do, I didn't see that line between the pics.

SB6

I believe that high temp burnt away the old original cat (in it since new i believe, thats 19 years) There was absolutely nothing left in there at all. As well as a few impacts from stones, speed bumps over the last year or two

Mar4ix

SB6 wrote: »

I believe that high temp burnt away the old original cat (in it since new i believe, thats 19 years) There was absolutely nothing left in there at all. As well as a few impacts from stones, speed bumps over the last year or two

When was last NCT , before this one, which you failed ?

JerCotter7

I just looked at my NCT sheet. My CO is 3.33% :eek:

SB6

Another thing that crossed my mind was the oil im using. Yes I know its my fault and is a no no if you care in any way for your engine, but there is very cheap semi-syntethic oil in it. But the valve stem seals are new and the bores are all good and I dont believe rings are faulty. It was just a thought about the HC level. Oil will be upgraded soon tho

SB6

Mar4ix wrote: »

When was last NCT , before this one, which you failed ?

Two years ago, tried to find the nct sheet but cant find it anywhere.......
I have a feeling that I said to myself back then looking at the results that there was something near failing, and I think that was emissions.

SB6

JerCotter7 wrote: »

I just looked at my NCT sheet. My CO is 3.33% :eek:

Thats ok I think if your car is from 96 -> 93.......NCT wise

Mar4ix

JerCotter7 wrote: »

I just looked at my NCT sheet. My CO is 3.33% :eek:

Id say that would indicate faulty coilpack , non working sparkplugs, faulty injector(-s). If you driving for long time in such conditions, your cat would be gone also.
Also your cars fuel consumption would be too high , and very noticeable, with hard starting bad performance, jerky ish driving and black smoke going from exhaust, when accelerating. ...

well one of those symptoms has to be in present with such high co.

JerCotter7

Should have mentioned I have no cat. And a lambda sensor is gone.

Mar4ix

SB6 wrote: »

Another thing that crossed my mind was the oil im using. Yes I know its my fault and is a no no if you care in any way for your engine, but there is very cheap semi-syntethic oil in it. But the valve stem seals are new and the bores are all good and I dont believe rings are faulty. It was just a thought about the HC level. Oil will be upgraded soon tho

It is hard to say, unless we will know what car , year, engine you are driving.

if stem seals are properly changed, but high oil usage still present, i think that would be oil rings.but how much oil your car is using,as there is number manufacturers, which says such and such oil usage is acceptable.

better use well named branded oils, they cost twice of those cheap one, but i think it is for reason.

SB6

94 spi 1.4 astra. Im prety sure that there is no oil burning going on. these cars are not known for it. I would say there is no oil useage however there is a leak from the sump.

I usually am the person getting the best oils for what ever Im driving, but it was not intended to still be driving it and college doesnt allow for fancy oils for it at the moment

SB6

I had a little thinky since the last post and may have over looked something. The results you seen above were the first and third test. The second (below) test was after me adjusting the timing and the lambda sensor.

So I had a look around the engine today and cheaked the points. They were mank. This was what was causing the bad combustion in the first place.
Have ordered a cap and rotor from motor factors (as well as a steering rack boot-cracked).


Thanks lads for making me think about it like I should of in the first place:)

galwaytt

SB6 wrote: »

So I had a look around the engine today and cheaked the points.

Points ? OMG - haven't seen them in years !

SB6

Sorry, when I said points I meant the rotor and dizzy cap contacts:)