I'm having this issue on my '99 where when I first start it up and get on the gas it bogs down real bad for a few seconds when trying to accelerate (5 seconds maybe). After that it is fine. Yesterday I tried to accelerate fast during this and it bogs down real bad then I heard a "pop" sound and it jerked forward and accelerated normal fast and then it was fine.

110K miles. Throttle body and intake are clean. No vacuum leaks as far as I can tell. New air filter, IAC is clean and my TPS is brand new. Spark plugs are only 3 months old along with the cap, rotor and wires. O2 sensors are both new. Nothing is leaking. No CEL or soft codes during my scan.

Once it has warmed up some my idle is smooth around 700 and everything seems fine. I do seem to be getting worse fuel economy lately, but it might just be in my head. Once it stops raining I am going to go out and check some fuses, maybe an O2 sensor fuse (wouldn't that give a CEL?). I don't really know where else to start looking at this point, so if anyone has any ideas I'd really appreciate hearing them.

 

Well all the fuses under the hood looked good, so I have run out of ideas for now.

 

Does this sound like a plugged up catalytic converter?