I have a few questions. I am getting closed loop a/f ratios of 14.7-15.3 at cruising and at idle. Should I adjust the closed loop map to richen the entire map a little? If so, how do I access this?

I am also getting extreme lean conditions at idle, slowly increasing back to 15. How do I tune for this?

Is it okay to run at 15-15.3 on closed loop? It seems that it is during a small enough load that it wouldn't harm the engine. MalibuJack, I know you are all over this.

I am running a 3" tbe, fuel pump, hks rs intake on an 06 ix.

 

Under cruise with little or no boost it wont hurt anything, it will add mileage in fact. I know a DSMer or 2 that cruise at 16.2:1 with low EGT's and 30mpg+. I ran this way earlier this year and was getting 27mpg with my 275 R compounds.

To answer your question I have altered the closed loop table and gotten resulting AF changes, though there was some discussion that the table didnt have much affect for others.

 

Also, you can check to make sure that you don't have any exhaust leaks before your wideband sensor, like at the connection of the downpipe and O2 housing. Even a small leak there would show slightly leaner than stoich burning during closed loop.

A good way to verify this is to check your fuel trims. If they aren't maxed out positive, then you are running a true 14.7:1 closed loop, but you may a have a small leak that is affecting the wideband reading. Or even simpler, your wideband may need to be re-calibrated.


Eric

 

maxed out positive, how do I look for this in evoscan?

 

I had a lean idle (17.5+AFR) that was due to an upstream exhaust leak in my DP, but it didn't show in the fuel trims at all, so don't put too much faith in that.

If the leak is downstream of the stock first O2 sensor but upstream of your WBO2, the ECU doesn't even know about it.

 

Right. I said to check the trims and if they aren't affected, then you know it's a leak. I was just giving him a way to troubleshoot whether or not he had a leak.

Eric

 

Sorry, I misread your post.