99 1500 z71 running lean
 

I have an occasional check engine light that comes on and my voltage will drop slightly and then go back up. Got Auto Zone to check it and said that the fuel is running lean. What are some possible causes? (Starting with the cheapest lol) I do have dual exaust if that matters.

When you say running lean, did it give you a bank 1 or bank 2 code. I would start with fuel filter first.

I don't know what bank code. Thanks for the tip, will check that out

bank means sides of motor, like bank 1 means I think the left side of motor is running lean. The reason I say this is because my 99 was running lean and luckily that was the first thing I went to and it ended up being fuel filter.

Ok. Makes sense. Thanks again.

I didnt realize it but I had a K&N air filter and the code was showing in bank 1&2. They said it was due to the K&N air filter because the grease off of the filter was coating the mass flow air sensor. They said if I switch back to a paper filter it would stop.

I have never heard of that but it seems legit. It is worth a try.