Originally Posted by Everet
You should really do the heater core as soon as you can. If the thing splits wide open while you are on a trip, you will be forced to fix it away from home.
19 mpg sounds low. Should be around 21-23 mpg.
Check the connections on the MAF sensor. I know that the best fix is soldering as Axe has written about it in a sticky.
Welcome to the forum and hope to hear more about your modifications and fixes as you progress.
Email me if you have any questions about the heater core or lifting it. everet@upyourkia.com
Everet


Thanks, once I get this thing running right and I know I can depend on it, I'll be contacting you for a lift kit.

Yesterday I went through the ignition system with a fine tooth comb, and every single piece from the ignition harness/pigtail down to the plugs are either verified good or brand new.

Put most of my progress in this thread: http://www.kia-forums.com/1g-1993-2002-sportage/207377-new-me-4x4-issues.html

Album of what I've done so far: http://imgur.com/a/pZxTI

Unfortunately, this is what I found when I got home from the test drive:

No Current Faults
------------------
Pending Fault Log
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P0303: Cylinder 3 Misfire Detected
P0300: Random/Multiple Cylinder Misfire Detected
P0604: Internal Control Module Random Access Memory (RAM) Error
P0301: Cylinder 1 Misfire Detected
P0304: Cylinder 4 Misfire Detected
P0302: Cylinder 2 Misfire Detected
P0101: Mass or Volume Air Flow Circuit Range/Performance Problem

It still surges, though not as bad, when accelerating, sometimes seems to have no power if I hit the gas when coming out of a turn, and intermittently idles low and rough.

Based on the black fouling on the plugs (pics in link above), it's been running rich, which I wouldn't be surprised destroyed/clogged the cat.

The only things I can think of to check now, that will allow me to have it back together and working so we can leave friday, are the ground points, ECU connections, and try to figure out if the cat is clogged.

I'm on the fence about replacing the downstream O2 sensor. It's switching the same as the upstream sensor.

I cleaned the MAF when I first got it, and watching the live data in Torque it seems to be reporting appropriate numbers.

Any other suggestions?