Technical Hi CO on emissions?

[dac69er]

My car really struggles getting through emissions.

I get a CO reading of about 0.5. The rest of the readings are fine.

I have fitted a new cat, O2 sensor, coils, plugs and a leads.

All sensors read ok according to iaw scan. I have replaced most of them anyway.

I have chucked some redex through the system too.

Any ideas on what to look at next? Running out of ideas

 

[jonjg]

Have you had any luck with your emissions test? Mine really struggles too. In fact, it fails every year and I have to weld a new cat in every time. Have you faffed around with timing at all? What size throttle body are you running? Personally I don't even know why they bother with emissions for cars over 20 years old, there aren't any cars older than 15 on the roads anymore!

 

[dac69er]

Have you had any luck with your emissions test? Mine really struggles too. In fact, it fails every year and I have to weld a new cat in every time. Have you faffed around with timing at all? What size throttle body are you running? Personally I don't even know why they bother with emissions for cars over 20 years old, there aren't any cars older than 15 on the roads anymore!

Haven't had this years MOT yet, but can't see it being any better.

I have tried messing with everything and have had no luck.

My Toyota starlet that is even older than my cinq (1989) is much better. It would pass the basic cat test and it has no cat!

 

[jonjg]

I think the trouble with the cinq is that the cat is nowhere near where it needs to be so takes ages to warm up, but if you have changed the cat you would have thought it would be ok? Mine only just went through with a new cat and Map sensor (near the ECU) so that might be worth changing? Other than finding a 'nice' MOT tester I'm not sure what else to suggest. I'm guessing you've gone for an Italian tune up drive before the MOT? And the timing is spot on? I have read about putting some ethanol in there with the fuel but I'm not sure that would do much good for the fuel pipes. Ashame as I think it really lowers the CO. Mine is out on the CO and Hydrocarbons by alot.

 

[dac69er]

I think the trouble with the cinq is that the cat is nowhere near where it needs to be so takes ages to warm up, but if you have changed the cat you would have thought it would be ok? Mine only just went through with a new cat and Map sensor (near the ECU) so that might be worth changing? Other than finding a 'nice' MOT tester I'm not sure what else to suggest. I'm guessing you've gone for an Italian tune up drive before the MOT? And the timing is spot on? I have read about putting some ethanol in there with the fuel but I'm not sure that would do much good for the fuel pipes. Ashame as I think it really lowers the CO. Mine is out on the CO and Hydrocarbons by alot.

I tried a few of the easy to change sensors on the last MOT and they made no difference unfortunately.

My mot tester is decent about it and considering the rest of the car spot on, he gets it through.

I always thrash it everywhere, so definitely not bunged up.

Timing is fine, can't do much with it tbh, as long as the cambelt is fitted correctly and the marks line up ok.

 

[JAMLAX]

Not sure if a £20 bottle of Cataclean would be any better than Redex...???

 

[dac69er]

Not sure if a £20 bottle of Cataclean would be any better than Redex...???

There is no dirt in my cat to clean, it was brand new and still didn't make much difference. I've cleaned my injector and fitted a new fuel filter. Fuel tank is only a few years old and I fitted a new pump at the same time.

It's always struggled to pass and I've changed most parts multiple times

 

[jonjg]

Have you replaced the fuel filter any time recently? I seem to remember changing mine before the MOT but then again I changed loads of bits to get it through.

 

[jonjg]

Sorry, didn't realise you had mentioned you had changed fuel filter.

 

[jonjg]

Out of interest what Cat did you replace it with? I bought one from BM catalysts which was absolute junk and half the size of the one I replaced it with.

 

[dac69er]

Out of interest what Cat did you replace it with? I bought one from BM catalysts which was absolute junk and half the size of the one I replaced it with.

I'm not going to lie, I bought a cheap one, but I was expecting it to do something, I honestly don't think it's doing much more than if I fitted a decat pipe!

It's probably just it being a cheap cat, but I didnt want to spend loads on one if that wasn't it.

 

[jackwhoo]

Look at o2 sensor voltage when hot and running in closed loop , if voltage going high low high low and so on then mixture is correct as far as ecu is concerned. Provided exhaust ahead of o2 sensor good and no misfired.
Any high co readings will be down to poor catalyst

 

[icheatatscrabble]

I think Cataclean does have some impact. My Sporting always used to be a little rich smelling on start up and then for a few minutes after. Hardly anything now. In a couple of months time I will definietly throw another bottle in.