So my gp failed its mot on the emissions test on the lambda (reading was 1.07) theyre saying that changing the spark plugs and putting and engine cleaner theough it (and a service) will fix the issue but when I asked if it would defo do the job the mechanic said 'nothing is 100%' which didn't fill me with confidence and id rather not spend £200 for it to fail again.

I guess I'm wondering if anyone knows whether that would be sufficent for it to pass the uk mot?

Also I noticed on the emissions paperwork he has the car listed as a 2012 evo amd mine is a 06 gp... would that change anything for the test and tolerances?

Thanks for any help.

Dya know what the pass level is to compare yours too?..A decent service..plugs,air/oil and oil itself with an oil flush would cost around £80 in parts.

What is your alternative?

Unless you want to spend around £130 on a Terraclean process...

Just checked prices on Euro Car Parts...with the current 35% discount its £53...plus £3 for an engine flush...

Yeah the upper limit was 1.03 for it to pass... they did mention something about a cleaning process, not sure if he said terraclean though. The all in price was £185 - thats for spark plug change, oil change and clean, the engine clean thing and the service. And to fix a small leak on the exhaust.

They never gave me any alternative.

Usually a high reading indicates a weak mixture, misfire and/or exhaust leak.

What were your other emission readings in your MOT?

And what engine do you have?

Spark plugs/oil AND the service?..meaning what?..what about the air filter?..

I guess you gotta ask what engine clean they are on about.

I have had 3 cars Terracleaned..it did make a difference AND lowered the emissions.You get a 'before' and 'after' emissions test.

I would also point out the have tested the incorrect car..dont they also take the vin?..

Don't know if this is of any help but I kind of inherited a Grande punto and it failed the emission s on the last mot and the garage put some addative in the petrol and then it passed however they charged labour for doing this,so just before the next mot a couple of weeks ago I bought a bottle of cataclean on eBay put it in the petrol tank 20 minutes before the mot went for a 70 mph drive to get the cat nice and hot and then went for the mot and it passed with flying colours with very low emissions reported on the mot sheet.

New oil is important for emissions! When was it last changed?
Change it + oil& air filters.

The exhaust leak , depending on where it is, will cause car to run rich/lean.

Did you take the car for a high speed, highway run before the MOT? This would help cleaning out the exhaust and the spark plugs.
Was the car hot enough? The CAT will need a nice long run before it starts working to 100% efficiency.

IAFYM said:

Also I noticed on the emissions paperwork he has the car listed as a 2012 evo amd mine is a 06 gp... would that change anything for the test and tolerances?

Thanks for any help.

Click to expand...

I'd first clear that with the MOT Guy, the 2012 EVO has possibly lower emission than a 2006 GP; >Euro 5 vs Euro 4 ?? So it might be that your car was in specs but they looked for tighter ones ...

Exhaust leak can fool the lambda sensors and therefore the ECU, which would result in an incorrect mixture; sort that one first and get a good service (plugs, filters, oil) to the car, IMO there is no need for terraclean or other similar treatment, tons of cars run fine without that BS... Finally get a nice highway ride just before getting to MOT, that will heat-up the cat and lower your emissions...

BRs, Bernie

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