will having a leak on my test pipe right after the header cause me to be running lean???

 

Probably not.
How do you know you're "lean"?

 

^ My question as well.

 

i got my car tuned couple months ago and i just recently checked my plugs after idling and theyre on the lighter tan side, instead of being brownish black.

 

Hehe ... I know I'm lean when my wideband keeps going between 15 and 16 under light partial throttle.
Getting it tuned Tues.

Lighter tan seems almost perfect, though its still hard to tell unless you do a WOT run and cut the engine off/and then check the plugs.

But in general, you seem to be OK.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">I know I'm lean when my wideband keeps going between 15 and 16 under light partial throttle. </TD></TR></TABLE>

thats how you know you are getting good gas milage lol....... i tuned my car that way on purpose under low load cruising speeds mine is usually low to mid 15's sometimes in low 16's

edit: to answer the OP thats not goin to make a difference....... now if it were full open header then it would be a probably

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94typeR &raquo;</TD></TR><TR><TD CLASS="quote">will having a leak on my test pipe right after the header cause me to be running lean???</TD></TR></TABLE>

if it does lean it out, it would be a fraction and nothing noticable, you have to remove the pipe at that point in order to change the a/f.. exhaust leaks are annoying and could lead to some powerloss. as far as plugs go, they have to have build up, be deformed/missing pieces and just look like they've been through lots of heat.. partial throttle = white, wot = black unless you're running lean.. but you don't turn your car off right after wot.. and, if you're not making tons of hp, as in nearly stock, its harder to damage engine just don't make a habbit out of it