ok i have it tracked down to cells 6, 10,11,14 and 15 all showing rich all but cell 15 are at a blm of 142 to 145 on cell 15 we are at 152 so i am adjusting my maf tables to bring this back in line at 126 to 130. i can find no vacuum leak and the car is stock as far as i can tell other than a descreened maf. can a desreaned maf cause this type of reading. also i can not find any exhaust leaks. So thanks in advance for any ideas. also fuel pressure is good

 

no info in your sig on your car's mods. That may help us.

Did you disable PE mode to get cell 15 readings?

don't look at this as a reading in certain cells but as the modification of the MAF table to match what is needed to bring your BLM's in line. Calibrate the MAF and your cells will follow.

Further, modifications of the MAF are not linear. Fine tuning will take literally hours when you are tuning across the whole MAF. Remember that cell 15 dominates 75% of the MAF scale. Pretty much what you are working with outside of cell 15 is partial tune and a small portion of the MAF table.

When I get ready to tune my MAF, I will get someone to help me post my MAF calibration spreadsheet I generated years ago.

 

as far as i know the car is stock other than a msd opti, electric waterpump, k and n filter, descreaned maf, and throttle body air foil. i am just worried that i will get the maf tuned and the blms follow but there is something wrong with the car, i mean 140 seems high for a stock car

 

First things first, you're not running rich. Blm above 128 indicates lean. That is to say that the o2's are picking up too much o2 to be at stoich. So if your blms are running at 145/128 the pcm is addint about 13% fuel. That means either your injectors arent delivering enough fuel, that your mass air sensor is faulty, or some other element of the calculation is off.

It could be old dirty injectors or some element of the fuel system is old or clogged or a weak pump. You could have a bad iat or faulty o2's for that matter. You could even have a misfire and the unburned o2 will cause it to add fuel when it doesnt need to. Even leaky exhaust will cause it.

OR it could be the ported maf, which alot of tuners including myself refuse to get near.

 

i am sorry i new it was lean. i have been thinking it was the maf. i am going to adjust the maf tables till it is where it needs to be. and then i am going to tune from there. thanks Daniel

 

I wouldn't do the no pe mode wot runs. Get it on the dyno and adjust it with pe values or adjust your maf there with pe enabled. At stoich that thing is going to get hot as hell wot and probably hurt the motor.

A better solution for you would be to tell the pcm you have smaller injectors if it was all off about the same before. So you can adjust it all globally with one constant instead of manipulating a lot of tables. Then flatten out the rough areas from there with the maf tables once the majority are close.

 

i thought about adjusting the injectors but i feel the correct repair would be use the maf so that is how i am going to adjust it. What i want is all of my blms around 126 to 130 then adjust my pe table from what should be 11.8 from the factory to about 12.5 with correct blms and them i might jump on some dyno time.

 

update. i adjusted my maf tables 9 percent across the board and now my blms are 133 and my fuel tables in pe are = to about 12.4 to 12.5 seeing that the pe fuel is not just one solid number. Car fells good and is getting bettery gas milage. I am going to try and get my maf tables closer. I just thought abut this. Can e10 cause you blms to be off?

 

You need to find out WHY its adding all that extra fuel. As WS6T3RROR pointed out, there may be a cause other than a miscalibrated MAF sensor. Changing the calibration table, without knowing for sure what the problem is may just be putting a band-aid on the real problem to cover it up. There is no reason a stock engine should need to add 15-18% extra fuel just to keep it at stoichiometric. You have to find the reason.

Yes, descreening the MAF will affect the calibration. But its not going to cause it to run lean across the full range of Cells. You may have a fuel pressure problem, the wrong injectors, a large vacuum leak, air bypassing the MAF sensor, faulty O2 sensors, etc.