I finally got my new catalytic converter and they put it on. Everything's great - my idle is smooth, car runs smooth, and the interior is quieter. Aftermarket cat sucked, so never go with one. By the way, now it runs a lot better.

My question: it seems like the shift hesitates, but more like it gets a bit "boggy" and slowly shifts. Takes too much time. I hit 100 mph and that's when they kick into gear and are ready for action. Not recently. What could be wrong, or do these just shift slowly?

'96 STS -- Thanks...

PS - O2 sensors replaced as well.

PSS - THIS IS AT WOT when it doesn't shift fast, that I know of. No codes. Vacuum leak? How do I test that w/o special tools?

Is the airbox supposed to make a sucking noise when I rev lightly in PARK?

Check the air filter about the sucking noise. It could be restricting too much and may also be what's causing your problem... When you go WOT, you car will switch to sports shifting mode and will almost redline the rpms before shifting. If the engine is having trouble breathing it may make it harder for it to reach the shift point.

Maybe so. It's been close to a year since I've had the air filter anyway, so I'll change it tomorrow. Know of a fair brand air filter? Low end, from like 1 to 2 is damn powerful (torque steer), but the topend is bad.

.......WIX, or you can throw away 10x the $ on K&N.

Advance Auto Parts here has ACDelco...
O'REILLY has the WIX! Perfect. :)