Vauxhall corsa 2002 - Failed Emissions on MOT tried everything?

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Sun 20 Mar 2022 20:54
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - Tony79

2002 corsa failed just over the limit on 2nd lambda reading, have changed both sensors, spark plugs, air filter, oil change, temp sensor, oil filter, repaired small hole in exhaust, cleaned throttle block, etc. Even had a camera put into the CAT and shows no breaks or anything. Still just over the limit to pass! Used lots of engine & cat cleaner. Mechanic said may be a little too much fuel going thru the engine? No faults on diagnostics and no Engine light. Diagnostics says sensors are doing their job and nothing jumping out to suggest what may be wrong? Any one have any ideas what else we could do?! All i can think is to fill it up with E5 petrol and see if that does it as its been using E10?!

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Sun 20 Mar 2022 22:42
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - Big John

Any exhaust leaks at all including clamped joints?

I had a few MOT issues with my old 2001 1.4 16v Octavia a few years ago that turned out to be related to a previous coil pack failure that had damaged the cat with unburnt fuel. Replacement restored normal service. Just suggesting as Corsa's are renowned for coilpack issues.

Edited by Big John on 20/03/2022 at 22:48

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Sun 20 Mar 2022 22:52
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - elekie&a/c doctor
Have you checked the front exhaust flexi section.? Hi lambda is often caused by unwanted oxygen in the exhaust system . What are the other emission readings ?
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Mon 21 Mar 2022 23:30
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - focussed

What I would do is:-

>Get the injection pressure checked, if the pressure is down even 10% to 15%, the injectors won't atomise the fuel properly. It's 20 years old, things like fuel pumps and pressure regulators start to wear out.

>Run the fuel tank level down to below 1/4 just above reserve, put some decent injector cleaner in the tank, Facom, Wynns etc. Run the engine for 30 minutes then leave it to stand overnight or as long as you can. Repeat the run and let stand routine as many times as you can then test again.

>If there is a slight improvement in the emissions, consider getting the injectors cleaned properly, again if the injectors are not atomising properly this won't help.

Use this small company, very knowledgeable, I've used them for motorcycle injectors.

www.injectortune.co.uk/index.html

Edited by focussed on 21/03/2022 at 23:38

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Tue 22 Mar 2022 09:29
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - bathtub tom
Use this small company, very knowledgeable, I've used them for motorcycle injectors.

I don't think I'd use any company that didn't put their address or phone number on their website.

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Wed 23 Mar 2022 00:15
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - focussed
Use this small company, very knowledgeable, I've used them for motorcycle injectors.

I don't think I'd use any company that didn't put their address or phone number on their website.

If you send a set of injectors for test and cleaning you are told the address to send them to.

He is a one man band + wife outfit and can't spend his working day answering lame phone calls for advice.

Edited by focussed on 23/03/2022 at 00:21

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Tue 22 Mar 2022 09:48
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - Falkirk Bairn

Having changed many items and still having issues

Try adding a few gallons of Shell V-power and after warmed up take it along a road for an Italian tune-up = low gear/high revs for a few miles.

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Tue 22 Mar 2022 12:01
Vauxhall corsa 2002 - Failed Emissions on MOT tried everything? - Andrew-T

Try adding a few gallons of Shell V-power and after warmed up take it along a road for an Italian tune-up = low gear/high revs for a few miles.

Although this is a petrol engine, when I add some V-power to my diesel, within very few miles I notice a difference in sound and feel, suggesting that some internal cleaning has happened. It may be the same for petrol. Certainly worth trying (if you haven't) as the cost is only about a quid.

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