That's right, I replaced my cat with a high flow model to try and get rid of the smelly exhaust under hard driving, well it fixed that but still one problem remains. My car ('99 GS auto) won't rev over 5K, as soon as it hits 5100 rpm it makes and dying sound, like it's bogging down, and then switches gears and it's fine. The car still runs great, it's just under hard acceleration that it does this. At first it wasn't bad, but I can't hit the pedal hard to pass someone without it hitting 5K and dying on me. What could be wrong? Spark Plugs, Wires, Too Rich, I need some help quick guys!

Try replacing your plugs and wires first if you haven't already.

Maybe one of the auto guys can give you better advice..

You getting CEL's???

Nah, I'm not getting CEL lights, the car runs great and idles fine. Just when I really hit the accelerator that it does this. I think it's the plugs and wires, I ordered some today so they should be in soon and we'll see.

dude, sounds like you're running on 3 cylinders or something? noticed any decrease in HP?

nah no decrease in power, I'm still running right at 3K rpm doing 80 mph on the interstate, which is same as before. This might sound really dumb but here goes my observation: I noticed for the first time tonight (under close watch) that it does it when the car shifts, not actually when it hits 5K rpm, so I stop the car and throw it into neutral and peg the pedal, sounds fine and dandy all the way to 6K with no sound or hesitation but when I let off the gas at 5K+ rpm it made the sound until the rpm's dropped to under 4.5K. Next, I dropped overdrive off and floored it, first hit 5500 rpm and then second hit 5600 rpm, both times not making the sound until the car was in the process of shifting. So I called a guy I know who has the same exhaust as me (Apex'i N1) and he said his does the same thing and that not to worry cause it was the back-pressure causing it to sound like this, and that it would only do this over 5K rpm. Anyway, my car has a full warranty still (another 15K miles) so it's going to Satan tomorrow for a thorough run-down and I'll let you guys know if it's serious.

no auto tranny here, but i think it may have sumthin to do w/the tranny computer....

the exhuast sound is prolly the "drone" or "whine" in the upper rpm range....

o ya, dun ferget the vasoline b4 your date w/satan ;-)

good luck

yea, you're on the right track. The mechanic that rode with me (he actually let ME show him) said he thought either my computer is going out or the transmission itself getting ready to go, at least gears 1 & 2. Something about those gears couldn't handle the high rpm range, thus the dying because they couldn't take anymore and were finally "forced" to shift. He was almost positive that's what it was and said they couldn't do anything until it finally goes out, he said it would be dumb to rebuild the tranny if in fact that wasn't it (for once they made sense) So, it wasn't my engine after all. Oh well, I needed new plugs and wires anyways.