WideBand not reading properly or what ???

[pgcanillas]

I need help with the following: I think my AEM Wide Band is not reading properly.
My car has an OEM 14b, an OEM I/C, 255 lph, stock fpr, 550cc, 2,5" exhaust, no cat, 2,5" downpipe, and an upper I/C pipe. I also have an Apexi AVCR, and a SAFC, plus an AEM WideBand, and a pocketlogger. My plugs are BPR6ES gapped at 0,28.
I am suffering of boost creep, so I decide to make the fuel upgrade, in order to do not have to worry about this. So I am running 17 psi, which is the lowest that I can.
I had my SAFC set at -16% in the upper RPMs (4500-7500) and I was at 10,7-10,8 AFR, but after 5500RPM, I was having a lot of knock (more than 20).
The problem is the following, if I put my AFR between 10,6-10,8, the car goes well up to 5600RPM, and then the knock start, and pull my timing up to 8 degrees (at 5500 rpm is 18 degrees), making the car slow.
So I checked my pocketloger to understand what was happening and I found that my O2 readings start at 0,86, and goes to 0,80 after 5700 RPM, so I richen my SAFC, and now in the first 3 gears the car does not knock at all. My AEM WideBand reading goes to 10 (The minimun that It reads) as soon as I am on the Gas pedal, but my O2 readings are at 0,90, and my car feels faster.
So, what do you think: Is my Wide band O2 Faulty? or what? Another important thing is that the car shows an AFR of 15,6-16,5, when the car is at idle, when it is supposed to be between 14,2-15,2. The only thing that I do not understand is that this O2 plus the AEM Wide band was in car that I sold, and was working fine on that car. THANKS!!!

PD: Excuse my English, I am from Argentina, and my natural language is Spanish.

 

[caged]

Can you do a sensor recalabration with the Aem? Have you run the car on any race gas? It is possable you have a bad sensor.

 

[big_d]

I think you're reaching the limits of that stock smic.

 

[mattdev]

The sidemount should be able to handle the 14b without issue... however, you SHOULD use a FPR for that 255 fuel pump. That could be a reason for the weird readings, however I seem to have the same problems you're experiencing.

Have you checked for exhaust leaks? I've written my issues off, since I have a decent sized exhaust leak before my wideband. If your using a stock o2 sensor in front, and wideband in the rear o2 sensor location, that is probably the issue.

 

[zhjiln]

get an aftermarket FPR for that 255 pump...

 

[pgcanillas]

Caged, No I can not do a recalibration, and I have never used race gas.
Big D, lets suposed that I am reaching the limits of my SMIC, so why if I put more fuel the knock disappears, and why do I have diferent readings in the Narrow and the Wideband?
Mattdev, I will check for exhaust leaks, but I am not able to hear anything extrange. Mattdev and Zhjiln, about the FPR, how can it cause the different readings between the narrow and the WideBand?
THANKS Everyone for your thoughs!!!!!!!!!!!!!!!!

 

[viperlp01]

Check for exhaust leaks at the o2 housing and at the head and exh mani. Those can throw them off. I leak at the head and my readings are a full 1 point off. If i try to run 14.7 it is just tooo rich so i run at like 15.8 and im solid.

 

[pgcanillas]

ViperLP01, I will check for exhaust leaks tomorrow. THANKS!