Running lean. Need advice.

I think my o2 sensors are probably going bad. Here is what's going on. I have a wideband and I see it going from 14.5-14.7 to 15.2-16 @crusing. I will be crusing around 50 running fine, come to a stop still fine then I get up to 50 again and it will read 15.2-16, stay there for awhile and then drop to the 13's and then to14.5-14.7. At WOT its 11.9-12.2. What could this be? I haven't done anything diff. Haven't changed anything out. My SSS was tune about 3000-5000 miles ago and I currently have 58000 miles. Can it be the o2 sensors?

dunno about a MC Radix but i like my cruising AF to be around 14-15 ;) dunno if it works the same.. but i am sure someone will let ya know lol


how drastic has it changed from the beginning?

If your air filter is the oil impregnated type, buy some MAF spray cleaner and clean it first and then see if you still have the fluctuation.

No its the AEM dryflow,no oil. I will try that tomorrow though. Thanks

Are the AFM for the 4.8,5.3and 6.0 the same.

What wideband do you use? I've seen the AEM's do this, might wanna get a second opinion on the a/f ratio with a new or another wb.
Use some logging software to determine if the O2's are toggling up and down, should be something like 20mv up to 900mv in a sine wave fashion.

I have the Areoforce gauge and I am using their wideband set up. with the gauge I can monitor my o2 sensors and at WOT they are at mid 800-910. They should be at the mid 900. I change out my o2 sensors with OEM densos and cleaned they MAF. I am still having the problem. What do I look for next?

During cruising, some wb's are going to fluctuate between 14 and 16, up and down. The main concern is that a/f ratio is about 11.5 under boost.
12.2 is a tad lean, might want to richen that up. Check the fuel pressure, make sure it's correct.
I would still get a second wideband to double check the a/f ratio. Just like all o2 sensors, they go bad or degrade.

I had the same problem with mine. It turns out I had a vacuum leak? I guess it was sucking in air while not in boost. In boost, my gauge was looking right with air flow ratio 11.7, but the truck felt like it was lagging. It would also surge at a stop. Now that the leak is fixed, it doesn't surge and the boost is so responsive now.
I don't know if this helps, but it sure helped mine.

The wideband is probably 2 months old. I can monitor my OEM o2s through my gauge and the reading are low also so the wideband is working fine. I have checked for vacum leaks but everything looks fine. I will bouble check everything .

An exhaust leak can also cause an erratic O2 lean condition.

Personally i would go a little richer while in boost, like what farmtruc said, 12.2 is a little too lean but not overally bad. And do a boost leak test ( introduce shop air into the intake system) Your tune can be just by a small little vaccum leak and would have to re-tune your fuel side again. What system are you using to tune with?