I need to know FROM SOMEONE WHO KNOWS FOR SURE if I can replace my bad 95 Maxima engine and auto trans with the engine and auto trans from a 99 Maxima. I know it can be done physically, but will it cause me any problems with accessory connections or smog (I live in California). Nissan says it is a straight swap but I notice that, when I look at parts catalogs, the engine component parts numbers vary from year to year. I don't want to buy the 99 engine and trans and discover after I put it in that I've got major problems.

If you can't be any more specific than "it should work", that won't help me any.

Thanks.

 

Change out the ECU and then you will not have any problems. Personally, I'd get a 95/6/7 engine, so that it can later be fitted with an aftermarket ECU. 99 were the most smog/restrictive of the 4th gen bunch.

 

It's a straight swap, but take the ECU from the 99 as well. There are a few extra goodies on the 99 intake manifold for smog. your going to also need the Y pipe from the 99 car with BOTH pre cats for that ECU to operate properly. (more 02 sensors, unless your cali spec motor already has them)

OR

Keep your ECU and swap the intake manifolds.

 

You may want to swap some parts over from your 95, the sensors, and manifolds should be swapped just so everything has the proper place to plug in.