Wideband Question

[tyler84]

Hello,

I have a 1999 Chevy 2500 with a 6.0 vortec. It has true dual exhaust, does this mean I will need two wideband O2 sensors?

Thank you,

-Tyler

[kbracing96]

No, the reading from one bank will be fine and the two should be pretty much the same unless you have some kind of mechanical problem. You can't adjust the banks individual anyway.

[Bruce Melton]

You might want to tune to the "odd side" (driver's) as if there is a lean problem # 7 is the most vulnerable.

[Sid447]

You might want to tune to the "odd side" (driver's) as if there is a lean problem # 7 is the most vulnerable.


I'll second that statement!
I had detonation in #7 hole and all the others were perfect.
(Fitted the older -pre 2001 4-point cylinder head coolant vent pipe to help alleviate this exact problem.

[CoryF]

Fitted the older -pre 2001 4-point cylinder head coolant vent pipe to help alleviate this exact problem.

is there somewhere i can find more info on this? -CoryF

[Sid447]

is there somewhere i can find more info on this? -CoryF

Okay,
info about this can be found in the book "How To Build High-Performance Chevy LS1/LS6 V8's."
by Will Handzell (Design Release Engineer for GM, then Program Manager for GMPP from 2003).
Book is from SA Design ISBN 1-884089-84-4 (www.cartechbooks.com (http://www.cartechbooks.com))

......In the section Production Parts for Performance on page 49.
It has a Tip:
quote......." Some road racers have been using the pre-LS6 steam tubes underneath the LS6 intake to improve cooling in cylinder number 7 (they previously had detonation problems in that hole). While the steam tubes weren't used on the factory LS6's, they will fit under the intake by slightly grinding down some of the stiffening ribs on the bottom side."..........unquote.

Description:- PIPE BLEEDER
GM PN:- 12562169

[CoryF]

Awesome!

I've actually got that book but have never had a chance to read through the entire thing. Maybe I should find some time. :) I bought it when I first got my Camaro, might turn out to be more useful then I thought.

Thank You,
-CoryF

[Bruce Melton]

Think there is a lean AFR thing going on with #7 also.

[joecar]

Why does this happen to #7...?

[Bruce Melton]

Why does this happen to #7...?

Wish I knew. Most of the busted engines we see seem to have hot piston- brittle ring lands or worse. The fuel rail- near side dead end- is a theory on #7.

The temp issue back there is easier to understand due to last in line for cooling. There can be air pockets back there as mentioned above.

Anyway, there seem to be two problems (related?) cooling and leanness converging on poor ole #7.