I just took some logs with my new alcohol injection. It works absolutely wonderfully but that's beside the point =) I noticed that my left o2 mv's are always .05 less than the right side at all times, WOT included. Also, my left BLM is always about 3 more than the right side at all times including WOT. It's weird though, on a WOT run the left side will be about 3-4 more than the right side, say 133/129, but once I shift or right after I shift they will both go to 128 and stay that way until I stop going WOT. During that time, even when the BLM's are 128/128 the o2 mv's will stay 0.05-0.06 apart.

If you are standing infront of the car look at the engine, which side is left and right if you are talking left and right BLM's. I have an exhaust leak somewhere on the driver's side that I have not fixed so I'm thinking that may be the cause of the o2 to be off. I just want to know what I'm looking at, how do I fix it, and what exactly does it mean? Why are the left/right values different? Basically I want to know what my car is doing and how I can fix it to be better =)

Thanks in advance.

BTW, I just emailed the log to Brian Herter explaining the same stuff I said on here. If anybody would like to take the time to look at the log please feel free to give me permission to email it to you

 

Yea I would check for an exhaust leak for sure. Since your BLM's are ABOVE 128 that would indicate that the car is running LEAN so the ECM is ADDING FUEL. But the car ISN'T really running lean, it's just that the o2's are seeing the extra air from the leak and it's throwing them off.

Also LEFT and RIGHT is determined from standing BEHIND the car. So left side would = the driver side.. right = the passenger side

 

You need to understand that there are numerous sets of BLM's, used as a function of RPM and MAP, idle, coast down, open loop, etc. You might find some helpful info in my ScanMaster writeup.

Not sure how much alcohol you are injecting, but since alcohol includes oxygen in its composition, it will alter the A/F ratio, as far as the O2 sensors are concerned. The stoichiometry of alcohol is not the same as gasoline. A maldistribution of the alcohol left to right bank could cause a difference in O2 sensor readings. Depends how much you are injecting.

 

Thanks for responding... My alcohol nozzle is on the passenger side of the intake elbow... you know how vortech has the divider going through it, the nozzle is the on the passenger side but I was told that it would not make a difference and that the alky would find it's way in. What I don't understand is that after I shift, both BLM's go to 128/128. I believe it was BLM cell number 18 during WOT, so I that is correct right?

I don't think that problem is being caused by the alcohol because if you will remember, I mentioned that it does that same split in o2 mv's and BLM's even when not in WOT (Alky only turns on at around 2*-3* of boost, basically at WOT). So I'm starting to think that it must be that exhaust leak on the driver's side that's messing me up. It would be the left side if it's the driver's side and that is the side reading a high BLM (lean). What about in terms of o2 millivolts, what is a good number to be at? What's richer/leaner? Does it match up with my BLM's???