i just installed my apexi neo tonight on my '02 s2k. we turned the car on and it was wanting to stall, and would not even want to rev. now i know whenever any type of modification is done, especially that to an ecu the ecu has to adapt. i've never messed with any type of tuner before or anything and i was wondering if it was doing this due to some type of preset the neo already has in it that is making it run funny or if the ecu just needs to adapt to the neo. also will it hurt my car running with the neo before a tune? i appologize for my ignorance on the matter, and i appreciate any advice/help that people that have done this before could give. i'm getting it tuned on monday or tuesday.

p.s. we just disconnected the neo from the wiring harness and the car was still running funny after the ecu had been reset and the CEL is still on.

 

Engine is SHUT;You need a new one=$10,000...

 

sorry but what?

to the OP: you need to mess with the preset, i don't know how different is vafc from neo but i did have to punch in some number for inital installation, dont just random number or expect the vafc to do it for you.

i wouldn't drive it if i were you, talk to some tuner and see if they can come and get the car to the dyno.

street tune will always never be as good as dyno tune

 

road tune is wayyyy better if you are not using a load bearing dyno. on the road your car can be running up to .3 A/F ratio leaner than on the dyno, due to increaded load. in some cases that Could potentially be hazardous

 

alright well i took out the neo (safc/vafc) and the wiring harness and just connected the original wires back to the ecu, runs fine again after driving. i'm taking it to battleground motorsports in atlanta on monday and i will reconnect it there and get them to dynotune it. we were originally messing around with it right before we went to this party, so i didn't have time to look up throttle settings or anything to get it to idle/run right so i just called it a day. yesterday we were at lake keowee all day so i figured i'd just leave it off today and let the people who know what they're doing mess with it. lol

 

Sounds like it would be worthwhile to dyno tune and then road test with the wideband to ensure AF is in safe limits. But most people aren't going to have a butt dyno as sensitive as a chasis dyno.