MOT fail on emissions, help needed.

Post by **Ash.Z** » Thu May 15, 2014 12:13 pm

Mate I have just removed one you can have.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu May 15, 2014 12:54 pm

Bludge wrote:how mich do you want for it wiggz? messaged preludemanh22 as he is selling the cat and downpipe as a set for 15 quid but he hasnt got back to me yet.

Yep, I've agreed to take that off him - need the downpipe for the bb4 (flexi is damaged) and I want to change the cat on lisa's BB1 because of the snapped off temp sensor in the current one

Bludge · Post by **Bludge** » Thu May 15, 2014 1:27 pm

Well im picking one up off ash tonight and will pop it on next week and go for a retest, if his is no good i'll be after yours w1ggz if you could hold on to it for me!

Post by **Thebusofwoe** » Thu May 15, 2014 1:35 pm

If still no good Chris, bring it up to Salisbury, i will pass it for you

no joke

BMCC · Post by **BMCC** » Thu May 15, 2014 1:41 pm

Looking at the test it looks like you are running a wee bit rich. A lambda of 1 is 14.7:1 air to fuel ratio (this is stoichiometric= exactly enough air to burn all of the fuel) while your results are all lower than 1. If the new convertor doesn't work then maybe a new o2 sensor might do the trick? (.95 lambda = 14:1, 0.9 lambda = 13.2:1)

judderod · Post by **judderod** » Thu May 15, 2014 2:12 pm

^ agreed. Your lambda is way off. Check every part of the exhaust manifold and downpipe before the o2 sensor for leaks. I take it you don't have a CEL? Check also your spark plugs for one unusual one in case you have one cylinder throwing off the mix.

Once you get the lambda sorted the other values will probably come back into line.

There's no point putting on a new converter with lambda that far off. Cats do nothing for lambda, and only work at or very close to lambda 1.

Bludge · Post by **Bludge** » Thu May 15, 2014 3:56 pm

damn, more complicated then i was hoping for.

Im pretty sure there are no leaks on the mani and mani to downpipe as i regasketed it all last year due to severe leaks.

Other then leaks and replacing the lambda sensor what else am i looking at?

Also does anyone know where i can get the gaskets for the cat if i do replace it?

Bludge · Post by **Bludge** » Thu May 15, 2014 4:02 pm

Well quite unbelievably we have lambda sensors at work, and they are in stock! will have to check for a price next week!

Bludge · Post by **Bludge** » Thu May 15, 2014 6:38 pm

Just changed the spark plugs and the old ones were swimming in oil and the gap between the whatsits where the spark goes (or something

) were vastly different on each plug, im guessing thats bad? i could almost fit my head in the gap on the nearside most plug!

So i whacked in some bosch super 4s, and im sure this will make me very unpopular, but i immediately noticed a pretty vast improvement, car seems to run a lot better, idles better and doesnt drop the revs when you clutch in as bad as it did before. also the exhaust seems a lot less smokey but that could be because its hot and sunny.

Is it possible that the knackered plugs could have been causing problems with the emissions? like an incomplete burn or something?

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu May 15, 2014 7:24 pm

Yes, they could e causing exactly that!