I just put headman lt's into 4" dynomax race mufflers i changed the plug wires but didnt cut them and elimated o2 sensor. now i have backfire and its really loud so i cant stay outside the car or else i'll go deaf. is it because i took out the o2 sensor or something else and how do i fix it? my cars an 84 firebird with carbed 305. it doesnt backfire at idle or it i rev it up slowly and it idles bad in gear.

 

If it's backfiring through the exhaust it sounds lioke a maybe 2 wires are switched around

 

yea thats what i originally thought but i was pretty sure i goy them right but i'm gunna go check now

 

My guess is on the backwards wires too. It's real easy to get a couple backwards if you don't mark them or double check all of them before you fire it up

 

yep i had two wires switched up only poped once after i changed it. but it still idles kinda jumpy in gear like from 400-800rpm but the problem i really wanted fixed is done so thanks.

 

you run a computer controlled carb? why on earth would you remove the oxygen sensor? removing the o2 sensor is going to cause a lot of problems.... its there for a reason.

 

yup O2 sensor is kind of important

 

i had to take it out to put in the headers and i had no where to put it back in. but im switching to non cc carb and eliminating the computer completely. i also had to cut the knock sensor in half because it rubbed against the headers.

 

I dont even think I'd drive it until I switched... No o2 sensor is bad enough. No knock sensor is even worse.

 

yea well it doesnt get driven anyways just started and pulled in/out of the garage.

 

Technically;

Back-fire is an explosion back through the intake manifold.

After-fire is an explosion out the exhaust.

Without the 02 sensor, the ecm will stay in open loop, and probably run too rich.

 

yea so pretty much im just switching to a a normal 600cfm holley and hope that will cure my idle problems.