Had to come back to the top after all of that. please put on a good reading comprehension hat cause looks confusing. Sorry it got so long winded.

Little history first. Bought this car in Feb. knowing that it needed some TLC under the hood. The car has 245k on the clock but mechanically it is still very strong. A few weeks ago I finally got around to getting the repairs done. New coolant bypass elbows. New gasket under the supercharger, new valve cover gaskets and new plugs and wires with the proper AC plugs. The car ran so much better and I was actually shocked as to how much power this car has. Lets just say the tires are quickly losing tread. LOL. Anyway, on to my still nagging problem.

The problem seems to be mostly after it has sat and cooled off completely. If I take off normally and just push the gas down the car seems to have no power at all. Its almost like it is bogging down.slowly pushing the gas pedal down just makes it worse. I can see the bost guage is building the boost, and the transmission is in a lower gear cause the tach is running high enough that this should not be an issue. If I just hold it there and wait it out it will take a few seconds but, just like someone has flipped a switch its like someone opened the gates of hell and unleashed the beats. This thing will snap your head back and take off like a rocket. If I let off the gas and stop at a stop sign or something it will do the same thing. It seems to go away as it gets warmed up.

Now for the next symptom. Every once in a while when I pull into a parking lot and go into a store or something, I will come out and start the car. It wont idle properly and the whole car just shakes. If I give it gas it wont even move the car it is so bad. Eventually it will just stall right where I parked it. Some times it will start right up and be fine, and others I have to start it a couple times and it will be fine. Some times I start it and it will move under its own power but it is right back to my first issuse where it will break your neck.

Now fast forward to last weekend. I was on my way home from work on Thursday. The car seemed perfectly fine untill I slowed down for a couple of 90 degree corners. as soon as I went to get back up to speed it was right back to no power again, and would not come out of it. This happened on both corners and every other corner I came to untill I got home. I shut it off and figured I would look at it when I got to work the next day. BTW I am a mechanic at a used car lot so I'm not totally stupid. Later that night I had to run to town to get some camping supplies for the long weekend. The car ran perfectly fine through the entire trip. Not one single issue. The next day I drove it to work without a singler issue as well. I get off work and drive home without a single issue. I jump in the truck and head out with the camper and the wife stayed home to wait for the kids to get off the bus from school. She called me later stating that she made it almost to town anf the car start acting the same way only it was so bad the the car just ran out of power untill it stalled like it would to me in the store parking lots. I got to the campground and unhooked to go see what was going on. Sure enough the car just shook and would not move untill it just died. I towed it off the road and into someones driveway and just left it there. We gave it a few hors to cool off and it started right up and ran fine and hasnt acted up since.

Now keep in mind through all of this, my origial problem of giving us whiplash has never gone away, even when I stated above that the car is running without issues. All of this driving is on country backroads. I live in a rural area where I can get up to highway speeds.

There are trouble codes for quite a few things but I didnt write them down and I fell most of them are being triggered because of the way it is running. I do know that there is a couple in there for the EGR and that is kinda where I am leaning at this point. My first thought was the supercharger bypass was sticking but I unhooked the vacuum line and it moves freely.

Thought I might add that this car gets worse gas mileage than my 1 ton dually Chevy with a 454 in it. Right now it is showing 15.4 MPG and I have confirmed this to be accurate a couple of times with a calculator at the pump

What all have you fixed, replaced and/or inspected?

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Bye Bye:

RIP sandrock

So far just what was listed above. Plugs and wires, gasket under the supercharger, halve cover gaskets, and cooland bypass elbows and checked to be sure the super charger bypass valve was free

I'd check out the cat, see if it's clogged. Drive the car at night, it'll glow red faintly if its clogged up. Also, inspecting the fuel system would be a good idea as well, especially the fuel filter. I would also disassemble and clean out the throttle body and all its sensors. It may be gunked up with carbon. After that, if the problem persists, I would check out the ignition control module underneath the ignition coils.

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-Car Guy Carl
"Penelope" - 2003 SLE - 247k Miles
"Sydney" - 2000 Honda S2000 - 98k miles

Guess I didnt mention that I cleaned the throttle body when I had it apart for the supercharger gasket. I'll look at the cat tonight when I go for a drive. I actualyy picked up a fuel filter for it last night. I remembered having a T-bird years ago that had a bad filter. It would run like this and if you left it sit for a bit all the crap would fall off the filter and settle back to the bottom. After driving it would get stirred up and plug it up again. I'm gooing to put it on Monday at lunch time and we'll see how dirty the gas is in it then.

This still doesnt explain my first problem stated in OP. I have a feeling this is going to be a multi step repair

OK here is the bok I had to write down for the trouble codes. I'm kinda leaning toward a sticky EGR valve but I just dont know. I just dont want to start tossing parts at it. The EVAP I know is the gas tank filler pipe. Some idiot was in there prying or something and gouged the sealing surface. A new one is like $500 and the junk yards around here wont pull one for me.

P0131 o2 signal low bank 1 sensor 1
P0135 o2 heater circuit bank 1 sensor 1
P0137 O2 signal low bank 1 sensor 2
P0300 misfire detected
P0404 EGR feedback signal out of range
P0440 EVAP system fault
P0442 EVAP system small leak detected
P1133 HO2s Bank 1 sensor1 insufficiant switching
P1404 EGR-2 position error/ EGR closed performance

Well I cleared all the codes this morning when I scanned it. When I left work tonight it did the hesitation thing again, and the CEL came on, so I ran back to work real quick and scanned it again and got P1133 HO2 bank1 sensor 1 insufficient switching. I just left the scanner on my lap the whole way home and watched all parameters and everything stayed normal and it ran perfectly fine all the way home. This thing is driving me nuts.

Maybe I should just order new O2 sensors and an EGR valve anyway. They could very well be original. I know the plugs and wires were all originals when I changed them with 245k on them.

When the O2 sensor went on my car, years ago it would do a similar thing. While driving on the expressway, maybe 10 minutes after starting the car, it would act as if the engine was shut off, yet was still running. Any minor change with the accelerator did nothing but make a small change in the rpm. Letting off the gas, or going WOT would put things back to normal.

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*Gone, but not forgotten* - Black 2000 SSEi, HIR Headlights, Angel Eyes fogs, 3rd brake light overlay, hi-flo cat, 180 degree thermostat, HS 1.9 rockers, LSx yellow springs, Intense FWI, PCM, shift kit, push rods, and 3.4 Pulley. ZZP Power Log.

Based on your mileage, you cannot go wrong changing both O2 sensors and the EGR. If they don't do the trick, go back to basics and check around for a misfire.

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2001 SSEi - NEW MODS in L32 - FWI, colder plugs, 180 t-stat, 3.5 pulley, 1.95 rockers, TOG headers and just about every Intense Trans upgrades they recommended.
OLD MODS in L67 - include FWI, colder plugs (Autolites), 180 t-stat, 3.4 pulley and 1.95 rockers.
(Previously owned '95 SSEi, RIP)