I just started tuning my G35 Vortech with Osiris a few days ago. Up until last yesterday it was idling, fuel trims were working.

In a thread on this site DJamps said he removed his foulers and had a better running car as long as you tuned out the DTCs for the cats.

I removed mine, and now the idle surges, AFR 18-22+. If you log only Fuel Mode it changes between closed loop and Open Loop Acc/Dec as it surges.

At initial crank up it is in Open Loop Start/Cold, and doesn't surge but idles high and as the idle drops towards normal, it kicks into the above surging issue.

At no point does the Short term or long term fuel trims change from 100%.

I put the foulers back in, reset the ECU. No change.

Help!

Thanks

 

Fixed the problem. I returned the ECU to stock, then reuploaded my tune.

I also noticed I had an ABS U1000 code that I cleared.