Dyno'd it....AF Ratio Problem...

[farmtruc]

For what it's worth, I never use my tail pipe a/f device because it's always a little off and isn't as consitant as the O2 bung reading.
I also found out on mine, that the dyno reads about .5 leaner than the street.
Bring it back down if you can't find a shop to dyno it and we'lld double check it, but I'm sure it's fine.
Also, you'd be surprsed that GM doesn't allow their trucks to richen up until about 5K rpms, doh. If PE delay isn't turned off, which yours is, then most trucks will not richen up until the top of second gear.
I know the '06's wont' until about 4900rpms.

let me know,
allen

[chrisj6]

Yeah I had to turn every delay box completely off on mine and set the enrichment rate at its max to get mine to richen up when I needed it to.

Chris