emissions problem for iva

[Watto GTR]

hi all took my car for iva today it failed on the emissions can any one tell me who can remap ecu stock ls7 with gm ecu thanks keith

[XTR2Turbo]

did it fail idle or fast idle test?

I would try Monkfish as I think they remap the Monaro.

Peter Knight might know but tends to use Motec

[Boosted LS1]

Also try Ringram on here as he's the EFI Live agent. Is you engine stock or cammed?

[Watto GTR]

thanks guys stock engine failed on idle and fast idle done some tests i now think its a faulty oxgen sensor

[XTR2Turbo]

I should just flag that when I tested my XTR2 it failed idle emmissions twice.

Third time I took my engine mapping guy along because he simply couldn't believe there was a problem.

Turned out that the SVA sensor was far too short - maximum about 25cm long.

So at idle as the engine pulses go down the exhaust at the exit there is actually air being sucked in and thi buggers the reading.

Sealed the exhaust exit around the probe with a damp cloth and it went straight through !!

On an Ultima with a large bore exit it will be even more of a problem. Less of an issue at higher revs though.

[GTR One]

My LS7 (Stock GM ECU) failed first time. Expecting the worse, I looked at O2 sensors etc but in the end it was just small air leaks in the exhaust joints. Once sealed it sailed through with great figures. May be worth taking a look.

Have you got anything to read the values from the ECU. You should be able to read the check the voltages from the o2 probes are cycling correctly.

Cheers, Liam

[paulbuckley]

Watto GTR said:

hi all took my car for iva today it failed on the emissions can any one tell me who can remap ecu stock ls7 with gm ecu thanks keith

mine sailed through the emmissions at Norwich - stock LS7 but remapped ECU - supplied by Andy Burrows at Gardner Douglas. Might be worth calling hime to see who maps his ECU's.... whereabouts in Norfolk are you?... I'm in Dereham