LS376/480 emissions problem

[chris2abel]

Im having problems getting my LS376/480 to pass the emissions test for the commercial light goods SVA.

The guy's doing the testing said it was quite common for the LS engines to fail. The exhaust emmisions are broken down into 3 sections, Lambda, Hydrocarbons and Carbon Monoxide.

I passed the Lambda and Hydrocarbons but failed on the carbon monoxide, you need to get 0.20 and i got 0.28 on average.

Its almost certainly down to the efficency of the Catalytic convertor i bought of ebay for £75. So im wondering if a bigger cat is the answer?

Ive read on this forum that its quite a common problem with this engine.

If the larger CAT does not work, taking the cam out seems like alot of work, is their anything else that i should be considering?

Edited by chris2abel on Thursday 25th November 16:10

[Paul.B]

There is plenty of info in the Ultima section on PH. You will need to trawl back a few pages but all the info is there. IIRC the concusions were to stick a std cam in to pass (IVA) the test.

[Magic919]

PM this guy for the answer - http://www.pistonheads.com/gassing/profile.asp?h=0...

[stevieturbo]

Paul.B said:

There is plenty of info in the Ultima section on PH. You will need to trawl back a few pages but all the info is there. IIRC the concusions were to stick a std cam in to pass (IVA) the test.

It sounds like he is talking about a van of some sort, as opposed to a car ? Havent a clue really though.

[eliot]

chris2abel said:

Im having problems getting my LS376/480 to pass the emissions test for the commercial light goods SVA.

There was a thread about the same engine and the same problem on the Ultima section I think. Appears to be that long duration cam which takes it from a std LS3(430bhp)spec to a LS376 which causes the problem.

[chris2abel]

Thanks for your imput ill send Craig an email.
Were going to fit a 400 cell Cat and see how much difference that makes before we try anything else.

Here's a photo of the truck before i fitted all the SVA compliant mud guards etc.