Backfiring when coasting

When I coast at higher rpm's the backfires are horrendous. I'm thinking it's my bad o2 sensor, and as soon as I can get it out of the housing to replace I will.

Any other causes?

do you have any exhaust leaks, that will make it backfire when coasting.

[iTurbo]

Do you have a code 15?

It sounds like a bad speed/distance sensor, or an intermittent connection to the SDS.

[MachineHead]

You may be running a bit lean. That is fairly common when you uprgade the exhaust. You can try to up the fuel pressure a bit and see if it gets any better.

[igotaneed4speed]

i have open 3 in exhaust on my car (5speed) when i coast down like, engine load it, it will pop hurendously out the pipe but thats cuz high engine vacum pulls the reg press down and lean miss fire.......... maybe thats what ur experiencing

Quote:

Originally posted by igotaneed4speed i have open 3 in exhaust on my car (5speed) when i coast down like, engine load it, it will pop hurendously out the pipe but thats cuz high engine vacum pulls the reg press down and lean miss fire.......... maybe thats what ur experiencing

sounds like it

what's the solution? raise static pressure? A new cartech RRFPR would allow me to set the static pressure and give me the benefits of a rising rate for higher boost.

[igotaneed4speed]

i rasied my static preesure bout 10 psi and put ina colder plug it cleaned up a lil but still is there i really didnt both trying to get rid of it i like to get next to them honders and gear load itto make it pop it scares the h*ll outa them

[GLHNSLHT2]

all my cars have popped when decel'ing. From my dad's 1970 carbed Porsche, to my 87 ShelbyZ and every car in between. Just compression popping. It happens when the a/f goes full lean, i.e. the injectors shut off and there is no fuel in the motor.

[TurboMinivan]

Something many people don't realize: your ignition timing influences the severity of the popping. IIRC, more retard = harsher popping.

FYI

I expect some popping with a free flowing exhaust, I've experienced it before, but this is ridiculous. It's not steady either, it sounds like hell.

[narcus]

I hear that... same problem for me after my exhaust "upgrade". It wasn't a normal pop here and there, it sounded like my engine was going to blow up. POW! POW! I adjusted my ignition timing a bit and that solved it right away.

Quote:

Originally posted by narcus I hear that... same problem for me after my exhaust "upgrade". It wasn't a normal pop here and there, it sounded like my engine was going to blow up. POW! POW! I adjusted my ignition timing a bit and that solved it right away.

Yeah the guy i bought the car from was a total @sshole, god only knows what he did.

*side note: he ran the car without an IC because the fullsize radiator was cheaper. Then when it ran hot he decided to take out the thermostst "that should make it run cooler". What an IDIOT.

did you advance or retard the timing?