ECU Codes 91 nsx

**NSX-SA** · 07-12-2006, 03:03

Can someone tell me if two long blinks with a pause then one long blink is either one code - 21 or two codes - 2 and 1. Engine runs extremely lean ( 16:1 ) from idle to 4500rpm ( vtech kit in ) then immediately done to 13.5:1 untill redline. Only thing that has change since last dyno run is Headers and Exhaust.

Any thoughts

**MiamieNeSeX** · 07-12-2006, 03:12

Originally Posted by NSX-SA

Can someone tell me if two long blinks with a pause then one long blink is either one code - 21 or two codes - 2 and 1. Engine runs extremely lean ( 16:1 ) from idle to 4500rpm ( vtech kit in ) then immediately done to 13.5:1 untill redline. Only thing that has change since last dyno run is Headers and Exhaust.

Any thoughts

V tech kit? Car is extremely lean, lean enough to cause serious problems.

Armando

**Larry Bastanza** · 07-12-2006, 04:10

It is a "21". That is the front VTEC selonoid. Not sure what you mean by VTEC kit, but the ECU is not happy about your front VTEC spool Valve operation.

before we are alrmed about your A/F ratio, how did you measure it?

HTH,
LarryB

**Briank** · 07-12-2006, 06:30

21 would be 2 long and one short with no pause, I your case is it sounds loke you are getting 2 and 1 which is front and rear O2 sensors.

**Jin1976** · 07-12-2006, 09:46

If the O2 sensors failed wouldn't the car runs rich?

Originally Posted by Briank

21 would be 2 long and one short with no pause, I your case is it sounds loke you are getting 2 and 1 which is front and rear O2 sensors.

**Jin1976** · 07-12-2006, 09:47

Did you smell unburnt fuel from the exhaust?

Originally Posted by NSX-SA

Can someone tell me if two long blinks with a pause then one long blink is either one code - 21 or two codes - 2 and 1. Engine runs extremely lean ( 16:1 ) from idle to 4500rpm ( vtech kit in ) then immediately done to 13.5:1 untill redline. Only thing that has change since last dyno run is Headers and Exhaust.

Any thoughts

**HKSboosted2** · 07-12-2006, 09:59

Originally Posted by NSX-SA

Can someone tell me if two long blinks with a pause then one long blink is either one code - 21 or two codes - 2 and 1. Engine runs extremely lean ( 16:1 ) from idle to 4500rpm ( vtech kit in ) then immediately done to 13.5:1 untill redline. Only thing that has change since last dyno run is Headers and Exhaust.

Any thoughts

Guys, I think he meant (Vtech Kick in)??

**NSX-SA** · 07-12-2006, 23:13

Hi Guys

Just to clear a few things up ( it was very late when i originally posted )

On the dyno the A/F ratio was sitting aroung 16:1 under wot from 1800rpm to 4500rpm with quite a drop in horse power compared to previous dyno runs with the std exhaust. As soon as v-tec kicked in it dropped to around 13.5:1 with a final horsepower increase of 28hp at 7500rpm over the std exhaust.

As i understand the ecu should go from open to closed loop ( or is it the other way around ) as soon as wot is achived. The change in A/F ratio seems to have been triggered when v-tec kicked in.

I hope this has made it clearer.