MOT Emissions Fail

[K T M Rider]

Car has failed big time on CO emissions at 0.896 against a max of 0.3%

HC also looks on the high side (compared to other peoples results on here) at 119ppm versus 200 limit - but given it's oil thirst I'm well happy that this one is still in (for now)   s:) s:)  

Not exactly surprised at an emissions fail, as I reckon oil use (with fresh 5w - 30) over the last 300 miles is in excess of 1/2 litre, so thinking maybe blocked cat / fouled plugs from excessive oil burning has given me the CO emissions fail.

Work done since I got the car:

Fitted new MAF (800 miles ago)
Fitted new Air Filter (right before MOT)
Replaced oil & filter (300 miles ago)
Removed pre-cats (300 milles ago)

Pre -cats looked perfect on removal (2000W car with 98,000 mlies).

My guess is that the old oil was thicker (maybe 10w/40) as oil use wasn't as bad (circa 800 miles per litre - so I'm talking relatively here)

Other thing is though, have driven the car quite hard and over distance in the last 300 mlies (was celebrating ditching the pre-cats) which could naturally also have given it a greater oil thirst.

Checking the OBD 300 mlies after ditching the pre-cats came up with a po420 code (pending), which again could point to a failed cat, although I did wonder at the time if it was reacting to me ditching the precats.

Gave it an ECU reset and nothing came back after 40 miles - still monitoring.

Am going to try thicker oil (5w40 or 10w40) / new plugs and a new cat.

At least my early roadster doesn't require a type approved cat  -just got one at an excellent price on Fleabay.

I'm hoping the nine miles to and from the MOT garage won't be enough to wreck it, after which I'll pop the old one back on of course  s:) s:)  

Any suggestions? (apart from save up for a new engine)

[Cap]

Check the Fuel Trims.. If bank 1 and Bank 2 are different from each other by more than 5, then you might have a faulty/Plugged injector..  that will also help cause High HC..  

Cap

[K T M Rider]

many thanks for the quick reply.

Pretty sure my (very basic cheapo ebay) OBD code reader can't check fuel trims.

Anyone got a more sexy code reader in the midlands they would be happy to try on my car?

[K T M Rider]

Just wondering, if I had a faulty injector, presumably it would typically throw up an error code e.g.

P0200 Injector Circuit Malfunction
P0201 Injector Circuit Malfunction - Cylinder 1
P0202 Injector Circuit Malfunction - Cylinder 2
P0203 Injector Circuit Malfunction - Cylinder 3
P0204 Injector Circuit Malfunction - Cylinder 4
P0261 Cylinder 1 Injector Circuit Low
P0262 Cylinder 1 Injector Circuit High
P0263 Cylinder 1 Contribution/Balance Fault
P0264 Cylinder 2 Injector Circuit Low
P0265 Cylinder 2 Injector Circuit High
P0266 Cylinder 2 Contribution/Balance Fault
P0267 Cylinder 3 Injector Circuit Low
P0268 Cylinder 3 Injector Circuit High
P0269 Cylinder 3 Contribution/Balance Fault
P0270 Cylinder 4 Injector Circuit Low
P0271 Cylinder 4 Injector Circuit High
P0272 Cylinder 4 Contribution/Balance Fault

In the meantime, going to try some Mobil 1 15w50 and put some miles on the car to see if it curbs the oil use. Decided that the Mobil 5w30 I've used is probably just completely wrong for the '2' (if you drive like me anyway   s:) s:)   ) as it is sold as a 'fuel economy' oil, so presumably formulated to primarily be a thin, low friction oil for engines that aren't worked very hard

[K T M Rider]

tank has just swallowed 33 litres of Asda's finest after a shade over 250 miles, which I get to be around 35mpg.

Given that I find it hard to drive the thing sedately, I think that's pretty good   s:D s:D

[K T M Rider]

This thread starting to mirror my life - friends are few and far between, so just end up talking to myself   s:lol: :lol: s:lol:  

Anyway took car back to MOT station today (after fitting new cat and spark plugs & changing oil to Mobil 1 15w50) and it sailed through   s:bounce: :bounce: s:bounce:  

HC down from 119ppm to 6
CO down from 0.896% to 0.009.

As Cap suggested I checked the fuel trims - all looked fine and performance and economy (35/37mpg) all seemed good to me over the 700 miles I did in the car between MOT & retest, so was happy that did not have an injector problem.

The P0420 ( Catalyst System Efficiency Below Threshold) code kept coming back, so together with the emissions fail, I just assumed that it was the Cat at fault.

Less than 48hrs before the retest I discovered that the post cat sensor simply wouldn't budge out of the old cat, so took the car back for retest with no post cat sensor - just filled the sensor hole in the new cat  with a suitable bolt!

Old spark plugs (NGK BKR5EYA11s) looked fine apart from the circa 2mm gap, I replaced like for like.

Going to 15w50 Mobil 1 has cut the visible oil burning at high rpm (judging by what comes out of the car when revving to 6k at standstill) so may also have helped a little bit on the emissions (HC?)  
Oil use still heavy though, but not sure if some of it is a leaking rather than all just burning off.

[frogger]

This thread starting to mirror my life - friends are few and far between, so just end up talking to myself   s:lol: :lol: s:lol:  

The opinions of others are overrated... generally speaking, some of the most intelligent conversations I have are with myself   s:lol: :lol: s:lol:  

Glad to hears its sorted!

[Cap]

You passed..  Great..  

Did you Post the Fuel Trims somewhere??..  It was not in this thread..  

The Spyder is not able to toss these codes..  

P0200 Injector Circuit Malfunction
P0201 Injector Circuit Malfunction - Cylinder 1
P0202 Injector Circuit Malfunction - Cylinder 2
P0203 Injector Circuit Malfunction - Cylinder 3
P0204 Injector Circuit Malfunction - Cylinder 4
P0261 Cylinder 1 Injector Circuit Low
P0262 Cylinder 1 Injector Circuit High
P0263 Cylinder 1 Contribution/Balance Fault
P0264 Cylinder 2 Injector Circuit Low
P0265 Cylinder 2 Injector Circuit High
P0266 Cylinder 2 Contribution/Balance Fault
P0267 Cylinder 3 Injector Circuit Low
P0268 Cylinder 3 Injector Circuit High
P0269 Cylinder 3 Contribution/Balance Fault
P0270 Cylinder 4 Injector Circuit Low
P0271 Cylinder 4 Injector Circuit High
P0272 Cylinder 4 Contribution/Balance Fault


That is why I wanted the Fuel Trims..  it would give me a clue as to what the ECU is calculating about the Fuel.. .But it looks like you were able to pass with a new Cat!..  Whew!..  

I'd still like to know what the Fuel Trims Are..  Long and Short, Bank One and Bank Two..

Cap

[d1bram]

Good to hear you have it sorted, would be interesting to see if you can find a leak which accounts for some/all of the oil loss.

[K T M Rider]

I'd still like to know what the Fuel Trims Are..  Long and Short, Bank One and Bank Two..

Cap

Fuel trims (recorded while driving) now uploaded to youtube.

Link:  m http://www.youtube.com/watch?v=Mu8ZclMR1qg m



Best viewed full screen, fuel trim data starts about 1 minute in.

Enjoy!!   s:) s:)

[Cap]

Thanks for the Vid.. Not much of a Story..   s:) s:)

a little hard to read, as I do not have a Load Value to go with the Fuel Trims..  , But Generally all looks well there..  Usually the Trims were in the Same Direction, and not that far from each other..  

Cap

[K T M Rider]

thanks to all for comments and assistance, have been racking up alot of miles in the car through work (3000 in the last 6 weeks) and (apart from oil consumption & timing chain rattle) car has behaved faultlessly.

Oil consumption seems steady at 500 miles a litre, have just got used to chucking in about a litre a week!!

mileage now stands at just over 101k, mpg regularly around 36mpg (even when fairly   s:twisted: :twisted: s:twisted:  )