Undoing a tune - do I need a new ECM?

[npmd]

Hello everyone,

I live in Massachusetts and purchased an LR4 from out-of-state that unbeknownst to me arrived with a tune. It failed emissions because the catalyst monitor is unsupported. It other otherwise drives great but I will need to undo the tune and turn on the catalyst monitor to pass emissions in MA.

My mechanic thinks it will need a new ECM and the dealer thinks either the existing ECM or an alternate used ECM can be reprogrammed. I've also read about owners rolling back the tune for emissions and then reapplying it, which I might be interested in depending on how it drives without the tune.

As far as I'm aware, the tune is software based in the ECM and there aren't any aftermarket parts like supercharge pulleys installed.

Can the existing ECM be reprogrammed back to stock?

If that is possible, how difficult is it to apply / roll-back a tune as needed for emissions testing, etc?

 

[powershift]

It depends on your smog rules. In CA if the ECM is modified with a tune then it will never pass even after reverting to a stock tune.

 

[npmd]

Thank you. So the existing ECM could be reprogrammed back to stock, correct?

I will ask my emissions contact if it can pass in MA with a reprogrammed ECM.

 

[Jimmy Brooks]

I’m not an expert on this but if you have a factory ECM you should be able to reflash it. If it’s an aftermarket clone then you’ll probably need to replace it. I don’t believe these ECMs are locked like modern day BMWs and other brands so it should be the factory one and you should be able to reflash.

 

[npmd]

I was told the ECM is VIN-locked and needs to be reprogrammed by a Land Rover dealer. I'll ask if either the previous or used replacement EMCs were factory or clones.

Per MA emissions, the ECM calibration number and ECM certification number need to be back to factory standards. Then all monitors need to be "ready" and there can't be any DTC codes.

This has been an ongoing saga but I just remembered that I initially brought it a Land Rover dealer who said the ECM was throwing a non-OEM calibration code and P0430. They recommended replacing the ECM, cats, and all O2 sensors. They quoted me about $22K.

My mechanic didn't think the cats would need to be replaced because of the mileage but perhaps the tune was not so kind to them?