I recently purchased a 2003 350z mt from a friend who had the car sitting around for a while, I went to get it inspected and it failed inspection. There were no engine lights or codes according to a scanner but overall readiness failed with a "Engine misfire: Unsupported". I think that there is somehow a tune installed on the ecu but the previous owner bought it from some mystery person in another state, and the previous owner barely drove it or even got it inspected. Somebody clearly abused this car in way that it would horrify you guys to explain so it would not surprise me if they messed with engine parameters in some dodgy way.

According to this thread I saw searching, this is possible to have the ecu re-written back to stock parameters, because there must be something that turned off the engine misfire test: https://my350z.com/forum/2003-2009-n...-to-stock.html

I'm picking it up from the dealership tomorrow, they informed me it's not possible for them to reflash it back to stock. Once the computer is re-written once it somehow locks out from being returned to stock and they wanted to sell me a $1500 replacement ECU. Now I'm bringing it to another dealership on Thursday and they are not sure they can reflash it either but their technician will at least try but I'm not sure if these dealers know anything or if secretly they're being truthful with me.

I'm not even sure this is the problem, I've been chasing ghosts in the car for the last year so it wouldn't even surprise me if there's something -else- going on instead. This makes the most sense to me so this is where I am now, but thanks for your help in advance

TL;DR - I think my car has a tune in it, is it actually possible to reflash it because I'm in the middle of being jerked around by the dealerships.

 

get the part number for the ecu, then check here

http://www.slidegood.com/nissan/350z?part_type=456

see if you can get it for around 200

 

Thanks for the reply, the next solution was getting a new ecu from a parts website so thank you for the link. I need the dealer to do all the technical work matching it up to the car if it comes to that right?

I just wanted to put a picture of the inspections report on here just to show in better detail what is wrong.
So tomorrow the car is getting dropped off at another dealership, the one i picked it up from today says it should pass but obviously it doesn't because i'm staring at a fail report. I read another topic about how the dealers can upload an oem binary to the computer, so once again i'm mystified as to why i'm told they cannot do it.

 

Sounds like you ran into a classic case of dealer ********ting. Never trust the dealer, especially regarding ECU issues. They know little to nothing and will just say "it can't be done" instead of admitting they don't know how. It can absolutely be done