I am not talking about the unit, I am talking about the Bosch LSU 4.2 sensor that almost all wideband units use. The Bosch unit's resistor that is caliberated from the factory tends to dull with use and differing enviro conditions. That is why you should do free air caliberation of the Bosch sensor every now and then. If you do not, then your readings will become less and less accurate with time. The sensor will still be accurate @ stoich, but in other areas it will not accurate.

 

Yes it was very irresponsible of Al. He stated to me that he could not add anymore fuel because he was lacking a parameter in his map definitions when he had tuned more than enough IXs to know that it was a fuel issue and not the map.

He continued to perform the tune and not tell me my fuel pump was bad because he wanted my money.

 

I was thinking that too. I'm wondering if he has his side of the story.

 

Fuel pump may only be part of the problem and your wideband may be dead on. If the pickup screens are dirty / clogged that will cause it to run leaner, I got .5 afr richer after changeing the pickup screens (one on the walbro and one in the other side of the tank on the end of the fuel pickup).

Could also have a bad FPR. Check your Fuel pressure at idel and at idle with the vacume line pulled off the FPR.

 

Only 3 counts of knock falling off quickly at 13.1 afr? I'm pretty sure my wideband is off.

My Fuel pump pickup screen was as clean as could be, but I'll check the other one as well, just to eliminate the possible errors.

 

How old is the sensor?

 

About 4 months old. The sensor was also out of the exhaust for a week while I was in the process of switching exhausts. If it got wet during that period, it would totally kill the sensor.