Hello all,

I recently got my truck back running after moving an oxygen sensor bung to the collector, instead of the #6 primary tube; and also added a new bung on the opposite collector (SBC w/long tubes). I am running a WB in one and a dedicated NB in the other. Both are new sensors and appear to be working properly. However, I cannot get the EBL to transition into closed loop. This is a new issue and I am 99% sure I didn't have this issue before. Although, it has been a little over a month since I began the project, and I cannot remember if I made any changes right before beginning the project. I tried searching through my BIN and other Bins provided by DynamicEFI, and I cannot see anything unusual, but thats not saying that I didn't miss something. Any suggestions on what else to check would be appreciated. For WUD indicators, the WUD doesn't register any faults, and it signals that the engine is running, closed throttle, idle, and launch mode. I haven't seen any other indicators. Oh, Im running an EBL Flash with the TT-1 WB unit. And using TunerPRO.

Thanks.

 

I found a posting by RBob talking about the Closed loop: CTS Threshold and I checked it out. The value was at 47

 

Are you running a heated NB sensor?

 

Yes, standard Bosch 3 wire.

As an update, I was able to tune in Open Loop, but still no closed loop.

 

Double check that the forced open loop idle flag isn't set:

Option Word 1 - Bit 2 - OpIdl

More then likely it is due to inactivity on the O2 sensor. Just letting the engine warm up in idle isn't enough to get the O2 moving around for the ECM to know that it is ready for closed loop operation.

Sometimes all that is required is to blip the throttle some, if not then a short drive will do it.

Note about launch mode (LM), most of the included calibrations have the delta MAP to enter LM set too low. Bump this parameter up to 5 - 7 KPa to prevent the ECM from going in and out of LM:

LM - Delta MAP Threshold Enter

RBob.