CTSC Reflash on 2006 Si - Too Lean?

COMplex · Post by **COMplex** » Fri Nov 16, 2007 3:47 am

I've had the Comptech Supercharger on my 2006 Civic Si since it was released: 10/2006

I installed AEM wideband A/F gauge soon after.

Since then, the car has been at around 12.5 at full throttle @ 4-5psi.

Within the last month or two, I've noticed that the car has been as lean as 13.5-14+ at full throttle @ 4-5psi. Partial throttle is anywhere from 10-12 usually.

I'm concerned that this may be too lean, and not sure what could cause it.

At first I thought it was because it was starting to get cold here in Denver (25-40? most nights) but during the day it is still 65? or so, and the A/F is still pretty high.

What could be the cause? And what should I check/fix if anything?

Colder temps?
Injectors? Fuel pump? FPR? Plugs?
"Winter" Gas?
Something wrong with wideband? Sensor?

So... is this dangerously lean? Should I stop driving until I find a solution? Any help is appreciated, Thanks!

Post by **Hondata** » Fri Nov 16, 2007 9:27 am

13.5-14:12 at 4 lbs won't kill it, but if something has changed then you need to find out what it is. 10-12:1 part throttle sounds wrong too.

What has been changed on the vehicle? Fuel pump, fuel pressure regulator, injectors?

Post by **Spunkster** » Fri Nov 16, 2007 10:38 am

What does the wideband read when the car is cold and not running, but wideband powered up?

SICivc · Post by **SICivc** » Fri Nov 16, 2007 1:06 pm

I have the same set-up. With the SC I have a AEM CAI, Comptech Header and Greddy EVO 2 Catback (Stock Cat still intact).

I use a PLX Wideband A/F. We installed a new bung, just past the Cat for the A/F sensor (not the best place, but closest we could get).

My A/F runs around 14.6 at idle and normal, non agressive driving. Whenever I shift or add throttle, it drops, but then returns to around 14.6.

Under hard throttle, the A/F drops off the gauge, goes below 10, but returns to hold at around 11 / 12.

Not sure if you concider it rich, but I have not had any problems. I was concidering trying the stage II pulley with this reflash (I REALLY want to get to 300hp to the wheels) but my mechanic at Dynospot strongly advised against it.

Btw, I got my Pillar pod at GlowShiftDirect.com.

COMplex · Post by **COMplex** » Fri Nov 16, 2007 1:17 pm

Hondata wrote:13.5-14:12 at 4 lbs won't kill it, but if something has changed then you need to find out what it is. 10-12:1 part throttle sounds wrong too.

What has been changed on the vehicle? Fuel pump, fuel pressure regulator, injectors?

Nothing has changed since I installed the SC, which is why I'm so stumped... I was planning on adding a race header soon, but not sure if I should find out what's going on first.

Spunkster wrote:What does the wideband read when the car is cold and not running, but wideband powered up?

Gauge reads 14.9-15.0 with the car off but gauge powered on. I started the car and it was 14.5-14.8 and upon turning off the car it read ---. Most of the time, if I turn the car off and leave the gauge powered it will read --- but then start reading like 17.2 with the car off still.

Post by **Spunkster** » Fri Nov 16, 2007 1:27 pm

What brand Wideband is this?

COMplex · Post by **COMplex** » Fri Nov 16, 2007 1:35 pm

Spunkster wrote:What brand Wideband is this?

AEM

http://www.aempower.com/ViewCategory.aspx?CategoryID=67

COMplex · Post by **COMplex** » Wed Nov 21, 2007 3:36 am

Any ideas? :(

Post by **Spunkster** » Wed Nov 21, 2007 10:39 am

Something soemwhere in the car has changed...You will have to start going over everything.