[heff]

in order for my car to pass Va inspection, i had to add catalytic converters. before i had the cats put on, the engine would have a sputtering miss pass 4200rpm, like it was running out of fuel. i added a secondary fuel pump, which helped, but didn't fix the problem. now that i have the cats and tail pipes that exit behind the rear wheel, the miss is gone, and it pulls strong with no misses, all the way to 5200rpm. what caused this to happen? was it the added backpressure the cats added? it also feels a little bit stronger when it's pulling hard,but that could be because of the miss i had before. just wondering. thanks for any input

[smagnotti]

Thats the almost too hard way to find out that your fuel mixture is lean. I would take a look at the spark plugs for signs of little round balls of purple/aluminum color, and if yoy see any you may have started to pound out your rod bearings!

[heff]

hmm...i thought my plugs looked good, a light tannish color, the strap on the plugs was burned about half back. i could smell a little bit of raw fuel at idle so i thought i might have been a bit rich at idle, and around town i'd get some puffy black smoke at long lights. i haven't heard any pinging, and i've been listening for it. i think i have 72s in my qjet at the moment.

[Skip Fix]

Added cats to my 81 and no change in performance.