350 tbi code 44 but plugs look really rich log attached

**Fabbe** · 04-16-2017

Hi, i am having trouble with my Chevy k2500 350 tbi truck, it started running really bad so the first thing i did was changing the O2 sensor then i checked the TPS and the MAP and everyting seems ok the coomputer code says lean and the injector duty cycle is showing 5-6--700% the plugs are full of gas..
Next i am going to change the manifold gaskets, that is the only thing i could think of, checked with carburator spray but couldnot find any leeks but i ran ot of ideas.
Anyone hav an idea of what iit could be? Attached a log file if someone could help me.
Thanks//Fabbe

**Fabbe** · 04-29-2017

Anyone that can explain how the injector duty cycle works? Is it from manifold pressure?

**jim_in_dorris** · 04-30-2017

Duty cycle cannot exceed 100%. That is static, wide open. If you are looking at a log to arrive at that conclusion, you don't have the patch enabled to display the Duty cycle. That being said, I would look at what the o2 sensor is doing and the rich lean counter and BLMs and INT's. If it just started doing it, I would look at things like is the ECM seeing the O2 sensor? is it going closed loop? If I knew what mask and ECM you have, I could look at the log and perhaps give you someplace to look.

**Fabbe** · 04-30-2017

Ok, thanks. I am using a 1227747 computer and mask $42.
¨
So would i have to burn a new chip to get duty cycle to work correctly or du you meen a patch for tunerpro?
Sorry for the noob questions but i am a noob! :)

**Fabbe** · 04-30-2017

i did another test drive and the o2 was really lean, attaching the log file. After i looked at the log file i decided to chane the manifold gaskets but there was no signs of leaks.

I also checked fuel pressure and it was about 11psi.