I just installed some after market headers on my 1500 pick up, 318 1997. It was a nightmare. Had some problems engine would bog found out it was because the ignition wires touched the headers and melted, so i replaced them also replaced the pcv valve because it was rattiling, that noise went away and I did a fuel system cleaning. Drove the car a bit around town today, everything seemed good, went out to eat and on the way back the car started to back fire again like it did before the ignition wires were changed. I do hear a slight exhaust leak, could this be enough cause to have the engine back fire and bog down? It only does this at low rpm and low speed about 20 or 30 mph and 2000 to 2500 rpm. Any one have any ideas on what it might be? The check engine light also went off, cleared it. But it didnt go back on last time i expirienced the back firing.

 

Did you route your wires correctly? There is a TSB on routing them.

 

An exhaust leak at the header(s) will cause your o2 sensor to read lean, and the pcm will compensate by throwing more fuel in there when you don't really need it. This can cause backfiring.

 

Oh ok, well then i guess i need to redo the headers. Is there any kind of silicone that can withstand the heat? i would like to maybe put some on the gasket so it would make up for the imperfections on the head where the headers mount.

 

try these gaskets and you won't have that problem:

http://catalog.remflex.com/product_p/rf6004.htm

 

Double check the wire routing and that they are on the right plugs