First, sorry if this is the wrong place to post, but I figure since it's mostly about the engine it goes here. I found a good deal on a JDM EZ30 and 6MT that I want to put into my XT6 (no problem with engine being newer). My question is, if I just put in a USDM ECU (or even the JDM one) will it pass California smog, or will I have to do other mods? I've read that if the JDM engine is the same as the USDM one it's fine, but it's not the same as the one in the car right now (ER27). Also, the car is currently registered in California but was originally sold in Washington, if this information is relevant.

 

(I'm assuming they don't care about the transmission 😂)

I don't know CA laws but if the car is going to be registered in CA I think it's not going to pass their sniff tests.  Don't they check to see if the engine is original? 

You can change the engine to a different one as long as its newer and the same vehicle class, you have to go to a referee the first time then you can do normal smog checks. My main question is if the JDM engine counts as certified for the other 49 states.

How much different is the JDM unit to the USDM unit?? 

If you’ve got the factory engine management that matches the engine type and all sensors are working properly I don’t see why it wouldn’t pass a smog test - assuming the test isn’t a standardised test for all engines in a particular class. 

Will the XT6 “mature” and avoid smog testing at a certain age? 

The EZ has to be better in the emissions department compared to the factory EA82 or ER27! 

My 20c from across the big ditch. 

Cheers 

Bennie

To my knowledge the only difference is the JDM version has some vacuum lines that the USDM version doesn’t. I don’t think the car will be exempt from smog unless the law changes, currently 1975 and older is exempt.