e-manage CAN be smog legal..meaning it is possible to pass a functional test and tailpipe test with it installed and tuned (not technically legal to use in some states or all maybe...but then again they'll never know unless you tell them). PFC cannot be smog legal. It won't pass the OBD functional test. Automatic fail. You can just take out the PFC and put your stock ecu back in (2 minute job) and your car will probably pass as long as your other upgrades are CARB approved. give your stock ecu some time and distance to adjust before you test...say at least 40 miles in various driving conditions to be excellent.
If you plan on Turboing your Celica and if you have smog tests in your area, you might lean toward the e-manage so you have a shot at passing smog. I highly doubt the stock ecu (you plugged back in after you took out the PFC) will adjust very well to a Turbo. Your engine may knock and blow up.
Some have said or implied it is easier to tune a Turbo Celica with the e-manage than the PFC. I don't know how true this is. Some *others* will probably say the PFC just takes more skill to tune correctly...ouch hehe. But the XS engineering Turbo kit does come with a PFC. But then again the same *others* may say that XS sucks and can't tune shit haha.
PFC has higher resolution than the e-manage on the fuel and ignition maps. 20x20 vs 16x16. On PFC you can adjust the vvti and on the e-manage you can't. On at GTS with the PFC you can adjust lift engagement but I don't think it's useful to be able to do this.
PFC is nicer for the GTS esp the 02 since you can adjust the rev limit.
PFC has no OBD compatibilty so it won't give OBD error codes. But as before, you can just plug your stock back in as long as you haven't boosted your car. e-manage is OBD compatible since e-manage is just a piggyback on the stock ecu.
Since PFC is a standalone you can directly monitor knock and other engine data through the Commander or Datalogit kit (not available anytime soon unfortunately). With the e-manage you would have to buy an expensive top-end $400-$500 scanner that monitors engine parameters like knock as well as giving you OBD codes.
Since the Datalogit for the PFC is not available soon, you might consider going with the e-manage since the support software is always available.
e-manage is about $850 cheaper than the PFC taking into account software for both (yes the FCDatalogit which you can't get). You can spend the $850 you save by going with the e-manage on installation of the e-manage and dyno-tuning it.
Whether you go with the PFC or e-manage have them dyno-tuned from the start and after each upgrade. Of course you can risk it with the base maps for either...but I wouldn't and others wouldn't.
PFC is easy to install yourself whereas the e-manage requires electrical connections in tapping in to the stock harness. You may have to pay someone to install the e-manage, increasing the cost.
On the webpages of some tracks in SoCal I see that they mention that no "computers" are allowed. I don't know exactly what they mean...like if this includes fuel computers or laptops etc. They can't find a PFC since it just replaces the stock ecu, but if they did search they would find the e-manage unless you have it exceptionally well hidden (but then it would be hard to access to plug your laptop into it). I haven't been to the SoCal tracks yet b/c I just moved here and am getting my car ready.
one more...for the e-manage + support software tool you need a laptop. For the PFC you should use a laptop with the Datalogit (which you can't get), but you can get by with the Commander.
There are probably many other issues I am forgetting to mention at the moment zzzzzzzz zzzzz...please others chime in now...
if you're curious...
I have an 02 GTS w/o the 8400 rpm rev limit conversion. I bought the e-manage, changed my mind, sold it, and bought the PFC. I was going to buy the Datalogit until I found out I couldn't get it right away. So now I am going to get the Commander until I can get the Datalogit. BTW I haven't installed the PFC yet because I am that worried about racing my engine without knowing how serious my knock is. I can't risk it. you don't know how much torture it is to have the PFC laying around like a loose, hot, naked, chick and having to resist doing anyting with it.
I love the thought of using the PFC, but I love my Celi even more.