New Black Pipe

[Deanohh_imp]

That was tongue in cheek because of all the theories on mufflers, mapping, air fuel ratios, popping, etc and their fixes. Lean would certainly account for running crappy but decel popping may be from something else.

the pair system at certain times lets filtered air flow via the pair valve into the exhaust so that the extra o2 can allow some of the incompletely burned gasses to finish burning. You hear this combustion as pops during decel. Can be other reasons for pops too. Usually pops that become more noticeable with a louder aftermarket pipe can be greatly reduced by blocking the pair hose(s) but this may cause more emissions and cause acid rain, melting of the north pole, dead whales, depletion of the Brazilian rain forest, etc.

The PCV did eliminate the running crappy at low speed but I would never eliminate almost all the popping with my Staintune by finding the hose from the air box to the pair valve, disconnecting the hose at the very front of the valve which is right below the tank between the 2 center spark plugs, jamming a short tight fitting socket head capscrew (16mm dia bolt head) into the hose and reattaching the hose so that no air could pass through the valve. Because if I did that it would be tampering with the emission control system which is not allowed.