85LSburb

iTrader: (1)

I got my 5.3 with a ls1 intake started a few weeks ago and it seems to idle fast. Warm idle is 850. The motor is stock except for the intake. I also don't have a exhaust on it yet. only a few inches past the collectors and only 1 o2 sensor is plugged in cause I don't have the bung for the other one yet. Can it be just the exhaust and only 1 o2 sensor that is very close to the end of the pipe or something else. This is my second swap and when I started my first on its idle was 500 rpm. Thanks.

bczee

iTrader: (12)

I would say get both of the o2 on.. and get some pipes on pass the colllector.. I am seeing somewhat the same with my Nova on 1st startup.. the O2 are about 1" inside of the collector flange and I have no exhaust pass the flange.. . it is idling high.

I am waiting to i get it over to the muffler shop before I make any adjustements to the tune.

BC

Rick Speed

iTrader: (55)

Yes if you have a leak with in 18" of an o2 sensor it will through it off.