Cracked drivers side header vs. BLM?


Active Member
Nov 21, 2011
So I was under the car yesterday and I noticed that the heat shield on the drivers header was loose and I start looking around and sure enough I spotted a hairline crack between 3 and 5 and I can feel the leak with my hand from the backside of the header at idle. My question is that my BLM is always a little on the rich side, typically about 118-123 at idle, never above 128. I thought a cracked header would cause a high BLM at idle? I was just getting ready to order a wideband and start tuning but looks like a new set of TA stainless stock replacement headers will be first priority.
A cracked header will also cause boost control issues. If the header has not been messed up from previous repair attempts you can have it tig welded with stainless rod at a shop and re-use it. Dont let any one try to mig weld it for you. If you do replace them I might be interested in buying your old ones.