pirate3

iTrader: (11)

installed long tubes, cat back exhaust, new plugs and wires and now it misses. You can hear it a little bit at idle but it is horrible at anything over part throttle. You can ease into and it will pull fine up to 6 grand but the second you stomp the gas it bucks, pops and backfires. Checked all my associated connections, ran an ohm test on the plug wires and they are all good.(within .010 of each other) O2 sensors are good and I let the car warm up to operating temp before driving it. the car has probably 30 miles since the install. And the fuel filter has maybe 100 miles on it.

BigFrosty

I had the same problem it turned out to be an exhaust leak.

edcmat-l1

iTrader: (10)

You probably cracked a plug. A header leak aint gonna cause a bad miss under load. Symptoms are definitely ignition miss related. Since it started after replacing the plugs, a cracked plug is your most likely cause.

Slowhawk

iTrader: (12)

I agree with the plugs.

NINE8TA

iTrader: (1)

I to agree did the plugs on my wifes blazer fired it up had a bad miss in number 5
pulled the plug and sure enough a cracked plug replaced it ran fine

pirate3

iTrader: (11)

Damn fine diagnosis fellas!! Swapped em out and she runs fine. Sounds good wound up against the limiter