3100 sfi. eghaust poping and backfiring

[steve-0]

ok so im looking for a cause related to my v6 swap in a 2001 cav, the eghaust crakles and gurgles when letting off the throtle. other wise it runs fine, the motor didnt do this in the doner car (96 grand prix 3100 small port) and as well the rad fan dose not kick on, have only got the motor up to 205 deg F so far. just finished the swap a couple of days ago and have put about 400km on so far, the wife needed a car to drive to work and running around. but any help would be great.

[Driver_10]

Popping is caused when there is an excess of HC in the exhaust with a lack of oxygen. It winds up burning post-cat resulting in those little pops and crackles. Factory air injection is designed to remedy this by injecting air "pre-cat" to encourage thorough burning.

[steve-0]

thanks for the rply, everything on the motor is as it would be in the pix. including the down pipe, cat and pipe all the way back to the rear frame. its using the stock ecm and bcm, i had to take the intire wirring harness out of the pix and run it in the cavy, no need for gages because i run stand alone custom gages already, so in thery it should run as it did in the prix, am i rong?

[steve-0]

ok i found a varry small vacuume leak and it seemed to improve, but sill pops and gurgle a bit, its not that is loud or any thing but woried about longjevity of the o2 sencers and pluging the cat.

[Driver_10]

ok i found a varry small vacuume leak and it seemed to improve, but sill pops and gurgle a bit, its not that is loud or any thing but woried about longjevity of the o2 sencers and pluging the cat.

I dont see any harm that can be done to the O2 sensors. Youre bound to have a bit of excessive Hc in the exhaust during closed throttle (which Im sure is where youre getting most of the popping). I see no eminent harm for the catalytic converter either.