5.7L running too lean (very high NOx), won't pass state emissions

[Kudzu]

There is a lot more experience in this thread than I have, but I will toss something out I ran into.

My suburban started running bad and I could see it in the data log it was running extremly lean and it was obviously much worse than yours is. I finally traced it down to one of the injectors being badly clogged and it wasn't flowing enough fuel. It was so bad you could see that one side wasn't like the other side. Both injectors were probably dirty and running lean, just one was really bad! I bought two new units and that fixed mine, if the chip doesn't fix that you might have dirty injector(s).

[bigmac]

Lack of fuel would definitely cause it to run lean. As soon as I get my computer back, I will carefully check the spray pattern. Moates is replacing the 24 pin socket and soldering in a new 28 pin socket. Once I get it back, I will drop in the ARJU (California) chip then check everything out.