Ok here is my problem when at idle my LT fuel trims are bank 1=12.2 and Bank 2= 27.4 everyt ime I dont get it my 02 sensors are new Im not missing I dont have a vaccuum leak so what is causing this my st trims look fine. Also I am getting a trouble code for P1441 EVAP Monitor Circuit High Voltage During Non-Purge please help me work this out. If anyone has autotap v2.04 I can send u my config and log file that would help alot thanks.

 

ttt

 

please someone I cant figure this out and I ned to soon

 

In my experience with Autotap, it's ok it for the LT Fuel trims to be positive or negative. All that means is that the PCM is having to make the same adjustments repeatedly to get the A/F ratio at the pre-cat o2 sensors to be 14.7:1 during part-throttle cruising.

The way the PCM works, is it measures the air at the MAF, adds X amount of fuel and checks the pre-cat o2 sensors to see if it's right. Based on the load, throttle position, RPM , etc... it determines if it's rich or lean and either adds or subtracts fuel. It is makes the same adjustment repeatedly (over a certain time frame), it moves those adjustments to the Long Term fuel trims and resets the short term to 0. It then starts the process all over again.

Now, positive numbers are where the PCM is adding fuel so I guess the PCM is seeing you as running lean so it's adding fuel at the particular point you're talking about. Since the throttle position and load changes quite often, the PCM has to keep track of the fuel trims for each of the fuel cells (I think there are 18 total)...

I am not a PCM guru, but I think I have a good grasp of the basics. You should read Fred's (Injuneer's) tutorial on the Scanmaster (it applies to Autotap as well) as it does an EXCELLENT job of explaining all of that stuff.

If you really want a copy of my config and one of my logs, email me and I'll send them to you, but if your car is running ok, then the LT Fuel Trims adding fuel isn't anything to worry about. No car is going to run at 0 all the time. The car is in a constant state of flux, going from rich to lean in order to keep the cats from becoming ruined.

 

It OK for the long term corrections to vary +/-5%, but if you are getting +12.2% on the drivers side, and +27.4% on the passenger side (are you sure it sais +27.4? Max correction is only 25%), you either have a poor tune, or a serious sensor or operating problem. The corrections are much too high, and they are significantly different from ank to bank.

First, what Cells are those numbers from? As noted above, there are 18 different Cells, and its unlikely that they all have the same value. Having the values for as many Cells as possible often helps identify the source.

What is the "85mm MAF"? Is it correctly calibrated for the LT1? Possible the airfoil is blocking the IAC opening? Any evidence of misfires or exhaust leaks before the O2 sensors? Both those conditions will cause elevated long terms.

Also, P1441 is "EEC system flow during non-purge". That might indicate a leak in the vacuum line from the EEC purge solenoid. That would elevate long terms at idle, but not in the higher load/hig RPM Cells.

If you have a log, post it as a ".csv" file, or an ".xls" file, and we can look at it.

 

This car no cats and no egr and no A.I.R also I am using sims for the post cat o2s. Is the purge solenoid its refferring to for the egr system? INjuneer I sent the csv file to you. I get decent vacuum too...like 16-17 and I know that is a cause of weird readings. Also the misfires are not real they are from the cam I just put new plugs and the otvc kit so I know that cant be it. What would cause o2s to go bad again because this would be my 3rd one in 6 months. Thanks for the help....Oh yeah and the KR is because my sensor is running a low voltage code so it automatically retards the timing when a dtc appears for it..must be a safety thing or something.