VFL

My truck is running awful! This came out of no where. The RPMs jump all over and will not smoothly idle. It grumples and idles like it's aftermarket cammed (which it is not.) It will run (barely) for a bit and then it dies. I'm throwing those two codes which are stating that both O2 sensors have "Signal Stuck Lean." I cannot locate any type of vacuum leak. Where should I go from here?

VFL

Bump. Has anyone had an issue like this?

rubbinsracin

have you tried cleaning your throttle body and MAF sensor?

I would unhook the battery, clean the TB (using TB cleaner, no carb cleaner) and MAF sensor (again specific cleaner) then do a throttle body relearn and see where you are at after that.

VFL

I have done both of those already. I'm going to attempt to change the upstream o2 sensors tomorrow morning to see if that is the issue. They appear to be original

VFL

Well O2 sensors made no difference.

rubbinsracin

Pull off your air box assembly and see if that helps.

Is you air filter plugged up?

techrep

iTrader: (1)

If its popping lean codes...its getting too much air...

rubbinsracin

True, however, on an 04 Trailblazer I had where the air filter was gunked up and the MAF sensor was then reading incorrectly, which caused it to throw funny codes. Im just suggesting steps to try that are cheapest first.

VFL

That's exactly what I thought, but I can't find a leak anywhere. I guess it's possible there's an intake manifold leak near the back.

rubbinsracin

when you cleaned your TB did you tear the gasket? possible leak there?