I bought a new Transponder key from Ace Hardware, they cut it to match my existing transponder key, then took their coding device out to my car, plugged in to the OBD and attempted to get the new key to handshake with the immobilizer. The tech couldn't get it to work and said it kept failing because I have an aftermarket radio installed and gave up. (BTW, I no longer have the stock radio, so not an option for me to swap radios). I now have a cut key that fits but is useless as it doesn't immobilize the immobilizer. Any workarounds or suggestions for DIY solutions? There are possibly places that can assist but that's another $150 or so and no guarantees...

 

I've never heard of such an issue due to an aftermarket radio. Sounds like the Ace Hardware person couldn't get it to work and looked for something to blame it on.

Dealer can do it 100%. Maybe some locksmiths if they have the proper equipment. There are also some "key programming" things you can buy on the interwebs, but no guarantees.

It could also be a faulty key. Might have to bite the bullet and just get one from the dealer, have them cut it, and program it.

There's some things you just can't skimp out on. Pay more for it to be done once and the right way.

 

I went the DIY route and it worked out.
Ordered a Simple Key programmer from Tom's Keys online - $63.
And bought some blank Nissan transponder keys online from Keyless Remotes - $23.
And had a local locksmith cut the keys - $14.

OBD programmer was pretty easy to use - just have to start with one functional key.
Radio has nothing to do with it, I have an aftermarket Sony.
Doors closed & hazard lights on are the only steps.
You "set" the programmer with a functioning key and it will only work on that car once set.
But you can make as many keys as you want - I made 2 in case one was a fail.
You can also program fobs for the car.

 

We can also just bypass NATS with an Uprev tune if you want. Take care of the immobilizer and you get a much more fun car to drive