WicketMike

iTrader: (13)

header to block.
header to ypipe
valve cover?

i am running really lean on bank 1. where should i start looking for a vacuum leak?

thanks

theblur98ss

iTrader: (71)

Did this just start all of a sudden? Is bank 2 reading normal? Make sure your intake is still tight. I've found mine working loose a few times.

WicketMike

iTrader: (13)

my bank 2 is reading normal and bank 1 is reading about 6% higher on the Lterms.

Pro Stock John

iTrader: (34)

Hmm check the intake manifold too.

WicketMike

iTrader: (13)

if theres a leak on the intake manifold, would i be only lean on bank 1 ?

theblur98ss

iTrader: (71)

Depending where the manifold was leaking it could only effect one side. If it's only one of the gaskets then it definately would. 6% isn't a whole lot really. You may try swapping your O2 sensors from side to side and see if the readings are the same. I would start looking at the header gaskets. Do you still have A.I.R. and egr on your car? That's a source. I've even heard of a leak right on the O2's

WicketMike

iTrader: (13)

i just installed O.E. 02's becuz of the problem and it didnt go away.

i got rid of the EGR but i still have the A.I.R.

ive never had a problem until of late. the bank 1 will read about 6.00+ and then bank 2 will be -.8
and its consistent thru out all rpms and mph

thanks

WicketMike

iTrader: (13)

doesnt the MAP reading tell you something?

my map at idle was at about 45 and on my other LS1 that is stock is only around 29 or so.

if its reading at 45 does that mean there is for sure a vacuum leak. or does the MAP go up becuz of cam etc...

WicketMike

iTrader: (13)

i got the plugs changed and the driver side header was alittle loose so it was tightened. but the car is still running alot leaner on the bank 1

dissonance

i would not swap the 02 sensor because if you have a leak it will damage the other o2 sensor, make 100% sure you have the exhaust leak fixed before you replace the 02, trust me i trashed 3 o2 sensors by doing this. the o2 will work for a few days and then die, if you have a leak the size of the pin tip it could cause a problem like this.

WS6 RULES

A good way to track down a vacume leak is to spray something like carburetor cleaner on the area you suspect. When sprayed on the leak the idle speed will pick up a bit. It's always worked for me. Good luck.