When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I've had my car for 2+ years, it's a pretty stock 03 Z06 with a vararam and a predator tuner. Never had any issues. Recently I'm getting a CEL and the codes are for L&R lean trim.
What should I be looking for?
Can I just richen it up a bit with the tuner?
retighten the air bridge connections behind your MAF
often it is an air leak letting un measured air into the throttlebody.
The vararam increases air volume and put the PCM at about its limits of adjustment. Any extra air ( new filter, ported throttlebody, leak) can put it over the edge.