Took the car for MOT today and everything passed with flying colours except the emissions. Readings are as follows:

 

Fast Idle Test

RPM: Min Limit 2350, Max Limit 2650, Actual 2549 - PASS

CO: Min Limit -----, Max Limit 0.300, Actual 0.154 - PASS

HC: Min Limit -----, Max Limit 200, Actual 28 - PASS

Lambda: Min Limit 0.970, Max Limit 1.030, Actual 1.072 - FAIL

 

Second Fast Idle Test

RPM: Min Limit 2350, Max Limit 2650, Actual 2500 - PASS

CO: Min Limit -----, Max Limit 0.300, Actual 0.1.09 - PASS

HC: Min Limit -----, Max Limit 200, Actual 7 - PASS

Lambda: Min Limit 0.970, Max Limit 1.030, Actual 1.080 - FAIL

 

Natural Idle Test

RPM: Min Limit 610, Max Limit 910, Actual 770 - PASS

CO: Min Limit -----, Max Limit 0.500, Actual 0.037 - PASS

 

So my question is what could be the issue? There are no fault codes showing and car has had MAF, Fuel Pump only a few months ago.

 

Any ideas would be much appreciated as I only have tomorrow to get it sorted and retested as I need the car for work on Monday.

 

Cheers

 

Dazz

I dunno if this will help but i remember my dad had a problem with emissions once and it was due to previous owner not giving it the beans enough. He gave it a good thrashing to clear it out then it passed the mot on re test.

Daft question but how warm was the car?

We have this problems on ferraris and we get around this by taking them for a massive thrash to get the cat hot and then find they pass second time round... Jus a thought

Oh and there is a product called cataclean that gad car parts used to sell that I heard did good things

Even the slightest leak from the exhaust will affect the Lambda reading, thoroughly check the exhaust for any blowing.  Your CO and HC are fine so I doubt very much that it's a problem with the cat or engine management system.

 

I've actually got one or two cars through the emissions test when they were going to fail on lambda by holding a cloth over the bit of exhaust that was blowing, though I did fail them on a major leak of exhaust gasses.

Edited 13 December, 201312 yr by fordfan
last paragraph added

If you have access to VCDS have a look in engine measuring blocks for the temp the ECU is getting from the coolant temp sensor. CTS failure is very common & will cause the ECU to fuel incorrectly. You can't rely totally on the lack of fault codes as the ECU will only throw a code if it isn't getting a signal or the signal is intermittent. Both the CTS & MAF sensors are good examples of this.

When was the car last serviced? If theres no eror codes on vcds then maybe a new air filter, plugs and an oil and filter change might improve things. If the engine is coked up as previous a terraclean would probably sort things out long term.

The lambda readings are way out, duff sensor probs.  Actually, when the one on mine went (the lambda value was OK but co was low and hc high)

 

Reading up suggests possible exhaust leak as fordfan mentioned.

Edited 13 December, 201312 yr by Liverpool-Lad

I'm surprised the garage didn't offer some advice.

Car isnt due a service but mite give it a go. No air filter as its a CAI. Looked at exhaust for leaks and only place is where the tailpipe fits to the main pipe. Mite pop some chemical metal round the the offending part. Left the car with them and I think he had 2 to do before mine so maybe not upto temp.

Ive put some cataclean in and will arrange to take it down tomorrow straight after a good thrash an see wot happens.

By the time it starts the second fast idle test, it would have been well and truly up to temperature.  During the second fast idle test you get a least 5 minutes of the engine at the specified speed.

 

There may even be an oil temperature on the report.

Another trick is to kick the **** out of it down the Mway just before the test !!!

Just take it for a thrash and it'll pass no problem.

You need to get the exhaust gas temperature up and sustain it. So you need lots of boost/load. Idling won't cut it.

Well ive put the Cataclean through it and patched up the exhaust leak on the tailpipe with chemical metal as a temp measure. Its booked back in for 11.30am and he has said to bring it down nice and hot and he will get it straight on.

 

So off for a good old italian tune up before I get there me thinks.

 

Wish me luck lol

Waiting ......... fingers crossed for you lol

Ok so after I patched up the exhaust I could still hear a blow coming from somewhere whilst I was at the MOT station. Luckily I know the guy who owns the garage so he allowed me to take a look underneath it on his ramp. Sure enough I found a small hole. I patched it up with the remaining chemical metal I had whilst it was on the ramp and then handed it over to him for the final test.

 

Results are as follows:

 

Fast Idle Test

RPM:  2624 - PASS

CO: 0.158 - PASS

HC: 11 - PASS

Lambda: 0.995 - PASS

 

Natural Idle Test

RPM: 763 - PASS

CO: 0.197 - PASS

 

So finally passed.

 

Think it mite be new exhaust system time though

 

Thanks for all the help guys. Oh and for anyone who isnt superstitious about Friday the 13th, First my car fails its MOT and then my central heating boiler packs in totally out the blue.......LOL

Chuffed it passed buddy but bad news bout the boiler......:(

Takeaway in the car tonite with the heaters on?????

Was going to say a leaky exhaust.