backfire caused by Catalytic converter?

[JohnnyIroc]

since i got the car when i idol it does this backfire i have tried a few things:
i got a new exhaust just because the one had a hole in it so i got a welded hush thrush the guy only cut half way to the catalytic converter and did custom pipes from there cause the factory's were too small
then the car started leaking coolant so i got a whole new head and it
still backfires!
i don't know what else it could any suggestions?

[RoadWarrior222]

Too much fuel, fuel at the wrong time, or valve timing issues letting unburned mixture out.

[turbovanman²]

What he said. Triple check cam timing and then ignition timing.

What car?

Have you done a compression test?

[GLHNSLHT2]

backfire or just a miss while idling? If it's just the miss every second or so no biggie as it's the baro solenoid opening checking pressure. now if it's gunshot sounding you've got something else wrong.

[shadow88]

I honestly haven't heard a 2.2L or 2.5L that doesn't sound like it's missing at idle. I'm with the others to varify it's an actual missfire, and not just a noise you hear through the exhaust.

[JohnnyIroc]

its a 2.5 non turbo
it is just a miss while idol
what could that be?

[turbovanman²]

its a 2.5 non turbo
it is just a miss while idol
what could that be?

What I posted above, let us know what you find out.

[GLHNSLHT2]

The miss is the baro solenoid checking atmospheric pressure. It's normal. Don't worry about it.

[turbovanman²]

The miss is the baro solenoid checking atmospheric pressure. It's normal. Don't worry about it.

True, I guess it depends on the severity of it. I never noticed TBI's to do that, they usually idle very smooth.

[JohnnyIroc]

well what can i do to get rid of it cause it kinda bothers me

[turbovanman²]

well what can i do to get rid of it cause it kinda bothers me

If its normal, you can't but if its that bad, its not normal.

Again, do as I suggested earlier.

Post a vid too.

[JohnnyIroc]

ill try to take a video but i probably wont till this weekend
when i have more time
and ill see what you say about it
but ill try to explain it for now
when ever it happens it makes a rattle and i notice the wheel shake a lot
and its never the same there's some that are real small and some pretty big

[badandy]

Not sure if this is the same issue by reading your description...but check the shutter in the distributor...so pull the cap and the HEP and check out the thing that looks like a crown and see if it's loose from the distributor base.

...the other thing to check is be sure your distributor timing is properly set...I had one backfire through the intake pretty badly before due to a friend and I got a little too drunk while finishing up a big job on the car and set the dist. waaaaaay off...lol...so I suppose if advanced too much it could backfire at idle.