ive had this problem for a while now and i want it fixed. while driving sometimes, not every time, the car while backfire out the exhaust usually not more than twice. i know its cammed but also during idle sometimes it fluctuates more than i think it should. and during start up if its the first time its been started that day if i dont help it idle down when it does it dies i need help solving this issue

 

Anyone?

 

was the PCM tuned for the new cam?

 

Why don't you try running the Scan94/95 software to see if it identifies anything ?

 

Ive never heard of that software definitely will be downloading it this evening, Thank You

 

Do you know where I can get a cable for this softwarre

 

One source is ALDL Diagnostics (link below).

OBD Diagnostics

 

Is this something that happens under any specific driving condition - decel, acell, steady cruise, high RPM, low RPM, all of the above? Do you still have a catalytic converter? Is the backfire accompanied by a misfire?

 

You should probably read the information that is in this forum about the Scan9495. It is on a Sticky that is located just a few items above your posting. It explains all the hows, whys, and all kinds of good stuff.

And if you aren't to familiar with this site, listen and respond as accurately as you can to Injuneer, the Super Moderator. He can answer just about anything if you give him good detailed info.

 

normally it happens under a load, 2500-3500 rpms and usually doesnt happen after i get out of 3rd gear. actually the car only has open headers those havent been installed for too long so i havent got around to going to the muffler shop. if youve ever heard a glasspack exhaust backpop after a rev think about that and add +10 on the noise. i dont really feel a misfire but im not too sure. the plugs are fresh so im about to change the wires now.

 

Glad to hear you're changing the wires. Freshly installed header screamed bad (melted) wire to me. The wire shorts for a second they falls away from the header and the next spark ignites the extra fuel...backfire...

If the headers are open you can be having other issues...the O2 sensors are right near the outlet and can get odd readings. Sometimes you get a lot of timing pull from the PCM knock circuit. Bolt on some turn downs or attach an exhaust system as soon as you can.

Do run a scan to see what's going on so other things can be ruled out. Check the fuel pressure

Good luck!

 

Yeah that was my initial thought was the wires. I have a borla muffler for the fbody so ill probably get that installed soon no cats so a O2 delete is in store for the car too probably

 

You can't delete the O2 sensors as they provide key info to the PCM for the fuel injection. You would get a preselected fueling based on other inputs...IAT, coolant temp, manifold pressure, etc., but it would be FAR from ideal. It's best to cap the headers and by that I mean move the outlet away form the o2 sensors...

 

is there not a dummy plug you can buy to plug the o2 sensor into for these cars?

 

Nope. Gotta have O2 sensor input for the computer if you want it to run right.