Ses Light

**LS1buckey** · 04-07-2008, 08:03 AM

My car threw some codes, I don't remember what the numbers were but the info on the codes were "manufacturer control air fuel metering" and "system to lean bank 2". I know bank 2 is the pass side and I'm thinking it might be the o2 sense I've had problems with it before the thing is I have replaced it 3 times already and I know it should not be going bad like that so often so I'm thinking I have other problems but not sure what they could be.
Any info would be much appreciated, thank you.

**sunsetorangess** · 04-07-2008, 03:12 PM

Any mods? Why did you replace the sensor twice allready?
Have the codes read and post them up so we can point you in the right direction, otherwise its a shot in the dark.
J

**LS1buckey** · 04-07-2008, 08:48 PM

I beleave it was a P0174. I have LT'S and a full exhaust, tranny tune 4L60E, and an emissions delete but I had the car tuned to not recognize things like the egr,air pump,secondary o2's. The reason I have replaced the upstreem o2 bank2 before is because of the same problem it keeps reading or atleast pulling a code for system lean bank 2. It's been about 4 months sense the last time I changed it. I was told awhile ago that a possable exhause leak at the headder flange pulling fresh air in could be the reason for my o2 to keep crapping out but never have confermed it. I will dubble check that code tomorrow morning and get back at you if it is different.

Thanks again.

**96slow6** · 04-08-2008, 10:39 AM

When you are replacing the sensor are you also clearing the LTFT's? If not you could very well keep throwing the code.

**LS1buckey** · 04-08-2008, 05:38 PM

Originally Posted by 96slow6

When you are replacing the sensor are you also clearing the LTFT's? If not you could very well keep throwing the code.

I'm assuming LT=long tubes but what's the FT?

**96slow6** · 04-09-2008, 12:31 PM

No, Sorry. LTFT is Long Term Fuel Trims. Its the accumualation of the short term fuel trims over time. If you just swap the o2's out with out clearing the trims it takes forever for the Long terms trims to catch up. So when the car sample the fuel trims it still shows lean. So It may keep throwing the code.

**LS1buckey** · 04-09-2008, 05:42 PM

no I haven't done that, how do you do it?

**96slow6** · 04-10-2008, 09:29 AM

Unhook the battery for about 30 minutes. That being the positive side not the neg.

**LS1buckey** · 04-10-2008, 07:34 PM

Will do, thanks man.

**Blownone94** · 04-10-2008, 10:20 PM

does the scanner you are using show you a data stream if so you can see what your stft and ltft are at when your only showing lean on one bank it can be a vacum leak on the intake runners for that bank, dirty injectors or exaugst leak before o2 on that bank. you can run a propane torch not lit of course along the edges of the intake to check for vacum leak if engine surges or changes you know you have a problem.

**96slow6** · 04-11-2008, 04:58 AM

An exhaust leak or vacuum leak will cause it to be rich not lean. The dirty injector is and Idea though. I have heard because you LS guys have no return line that the rails in the back passanger side can get dirty and clog the injector?

**LS1buckey** · 04-11-2008, 06:13 PM

I think if it is an exhaust leak before the o2 then the fresh air is just causing the o2's reading to get all messed up but I can see how it would be rich not lean because thats the engines defult to go rich if it thinks theirs a problem better more gas than less gas.